Busyspr Biochemistry.docx

20 random questions for Best of 5 Test Options for Questions 1-1 A DNA: ribose sugar, no uracil and no purine bases

B

C

DNA: purine and pyrimidine bases, uracil, no ribose D sugar

E

DNA: 6 carbon sugars, purine and pyrimidine bases, no uracil

RNA: ribose sugar, uracil, purine and pyrimidine bases RNA: 6-carbon sugar, uracil, purine and pyrimidine bases

Question 1 With respect to the structure of nucleic acids

Options for Questions 2-2 A Nucleotides linked by 3-5-phosphodiester bonds

B

Ribose linked to deoxyribose by hydrogen bonds

C Nucleotides linked to ribose or deoxyribose

D

Purine bases linked to pyrimidine bases by hydrogen bonds

A DNA has a left-handed double helix structure

B

The DNA helix has 12 bases per turn

C The DNA helix completes a turn every 20 nm

D

Heating to 90 degrees C causes irreversible denaturation of DNA

E

Purine bases linked to ribose sugars by 3-5phosphodiester bonds

Question 2 Nucleic acids are formed from

Options for Questions 3-3

E

Complementary nucleotides are held together by hydrogen bonds

Question 3 With respect to the structure of nucleic acids

Options for Questions 4-4 A Are highly acidic proteins

B

Are negatively charged proteins

C Are rich in arginine and lysine

D

Are rich in valine and alanine

A H1 / H5

B

H2A

C H2B

D

H2C

E

Interact with the positively charged ribose group on the DNA molecule

Question 4 Histones

Options for Questions 5-5

E H4

Question 5 Which one is not a recognized family of histones

Options for Questions 6-6 A Single-stranded linker DNA

B

Double-stranded RNA

C Double-stranded linker DNA

D

3-5-phosphodiester bonds

E hydrogen bonds

Question 6

With respect to the structure of DNA and chromosomes, nucleosomes are joined by

Options for Questions 7-7 A Double-stranded DNA bound to histone H1

B

Double-stranded DNA bound to histone H2

C Double-stranded DNA bound to histone H4

D

Double-stranded DNA bound to histone H2A

E Single-stranded DNA bound to histone H4

Question 7

With respect to the structure of DNA and chromosomes, nucleosomes are joined by

Options for Questions 8-8 A Cannot be detected by Northern blotting

B

Can be detected by Western blotting

C Can be detected by Southern blotting and PCR

D

Cannot be detected by PCR

A Has a 3-methylated cap

B

Has a 5-poly-A tail

C Has a start codon AUG

D

Has a sequence that is written in the 3- to 5- direction

A Makes up about 80% of total cellular RNA

B

Is more stable than ribosomal RNA

C Has a secondary structure with hairpin loops

D

Makes up about 99% of total cellular RNA

E Can be detected by Northern blotting and PCR Question 8 Messenger RNA

Options for Questions 9-9

E Contains the base Thymine Question 9 Messenger RNA

Options for Questions 10-10

E Is broken down rapidly after transcription Question 10

Messenger RNA

Options for Questions 11-11 A mRNA is more stable than rRNA C

mRNA does not have a secondary structure while rRNA has a secondary structure

B

There is base-paring within mRNA but not rRNA

D

mRNA does not have a poly-A tail while rRNA has a poly-A tail

E mRNA is 80S in size while rRNA is 40S or 60S Question 11

With respect to the differences between mRNA and rRNA

Options for Questions 12-12 A 5% of total cellular RNA

B

15% of total cellular RNA

C 35% of total cellular RNA

D

55% of total cellular RNA

A Has a 3-methylated cap

B

Has a 5-poly-A tail

C Has an amino-acid binding site at the 3-end

D

Has an anti-codon at the 5-end

A A primer is required for mRNA synthesis

B

Both the sense and the anti-sense DNA strands are transcribed

C Only the sense DNA strand is transcribed

D

The mRNA is synthesized in the 5- to 3- direction

E 85% of total cellular RNA Question 12

Transfer RNA makes up

Options for Questions 13-13

E Has 40S and 50S sub-units Question 13

Transfer RNA

Options for Questions 14-14

E Any incorrect bases are removed by nucleases Question 14

During transcription

Options for Questions 15-15

A Addition of exons

B

Removal of exons

C Addition of introns

D

Removal of introns

E Conversion of introns into exons Question 15

Post-transcriptional mRNA processing includes

Options for Questions 16-16 A That begins with 5-GU

B

That ends in 5-GU

C That begins with 3-AG

D

That begins with 5-AG

A The cell is haploid in the G2 phase

B

The cell is diploid in the G2 phase

C The cell is tetraploid in the G2 phase

D

DNA synthesis occurs in the G1 phase

A The double helix is unwound by DNA ligase

B

The double helix is unwound at 20-80 sites forming Okazaki fragments

The leading strand is synthesized in Okazaki fragments

D

The action of DNA helicase produces 20-80 replicons

A Recognize specific amino acid sequences

B

Recognize specific proteins

C Recognize specific nucleotides

D

Recognize specific polysaccharides

E That ends with 3-GU Question 16

Introns have a sequence

Options for Questions 17-17

E DNA synthesis occurs in the M phase Question 17

During the cell cycle

Options for Questions 18-18

C

E DNA polymerase beta synthesizes the leading strand Question 18

During DNA replication

Options for Questions 19-19

E Recognize specific DNA sequences Question 19

Restriction endonucleases

Options for Questions 20-20 A Western blotting

B

Southern blotting

C Northern blotting

D

Eastern blotting

E Fluorescent in-situ hybridisation Question 20

Which of the following laboratory techniques is used for RNA analysis?

50 random questions for Best of 5 Test Options for Questions 1-1 A

The 3-5-phosphodiester bonds are broken by heating B to 90 degrees C

The complementary DNA chains are separated by heating to 90 degrees C

C

The deoxyribose sugar molecule is destroyed by heating to 90 degrees C

Purine and pyrimidine bases are denatured by heating to 90 degrees C

E

Purine, but not pyrimidine bases are destroyed by heating to 90 degrees C

D

Question 1 With respect to the structure of DNA

Options for Questions 2-2 A

Is a fragment of DNA once it has been cut by a restriction enzyme

B

Is a bead formed from DNA wrapped around histones

C

Is a chain of nucleotides joined by 3-5phosphodiester bonds

D

Is a bead of highly basic protein found within the nucleus

E

Is the remnant of the cell nucleus following apoptosis

A H1 / H5

B

H2A

C H2B

D

H2C

Question 2 A nucleosome

Options for Questions 3-3

E H4 Question 3 Which one is not a recognized family of histones

Options for Questions 4-4 A

Are segments of DNA following digestion by restriction enzymes

C Are units of size for mRNA

B

Are units of size for DNA

D

Are individual turns in the DNA double helix structure

E Are segments of non-coding DNA

Question 4 Svedberg units

Options for Questions 5-5 A Contains introns and exons

B

Does not contain exons

C Does not contain introns or exons

D

Does not contain introns

A DNA

B

rRNA

C tRNA

D

mRNA

E Can contain both introns and exons

Question 5 Mature messenger RNA

Options for Questions 6-6

E tRNA bound to mRNA

Question 6 Which nucleic acid has a clover-leaf secondary structure?

Options for Questions 7-7 A A primer is required for mRNA synthesis

B

Both the sense and the anti-sense DNA strands are transcribed

C Only the sense DNA strand is transcribed

D

The mRNA is synthesized in the 5- to 3- direction

A Occurs when some introns are not spliced

B

Occurs when some exons are spliced

C Is part of RNA editing

D

Results in addition or substitution of nucleotides

B

The double helix is unwound at 20-80 sites forming Okazaki fragments

E Any incorrect bases are removed by nucleases

Question 7 During transcription

Options for Questions 8-8

E Does not occur in eukaryotic cells

Question 8 Alternative splicing of mRNA

Options for Questions 9-9 A The double helix is unwound by DNA ligase

D

The action of DNA helicase produces 20-80 replicons

A Are enzymes

B

Are phospholipids

C Are histones

D

Produce Okazaki fragments

A ATATAT

B

AAATTT

C AATAAT

D

ATTATT

C

The leading strand is synthesized in Okazaki fragments

E DNA polymerase beta synthesizes the leading strand Question 9 During DNA replication

Options for Questions 10-10

E Are used in the polymerase chain reaction Question 10

Restriction endonucleases

Options for Questions 11-11

E AATTAA Question 11

Which one is a palindromic sequence?

Options for Questions 12-12 A Recognize specific amino acid sequences

B

Recognize specific proteins

C Recognize specific nucleotides

D

Recognize specific polysaccharides

A Northern blotting – DNA

B

Southern blotting – DNA

C Western blotting – RNA

D

Eastern blotting – mRNA

E Recognize specific DNA sequences Question 12

Restriction endonucleases

Options for Questions 13-13

E Western blotting – DNA Question 13

With respect to techniques used to detect macromolecules

Options for Questions 14-14

A Bacteria that have ingested white blood cells

B

White blood cells that have ingested bacteria

C Bacteria that have been infected by viruses

D

Bacteria that can be infected by viruses

A Fragments of DNA outside cells

B

Fragments of RNA outside cells

C DNA species that can replicate outside cells

D

DNA species that can enter cells and replicate within them

A Alanine and arginine

B

Arginine and lysine

C Methionine and serine

D

Glutamine and aspartate

A Glutamine and asparagine

B

Glutamine and glutamate

C Arginine and methionine

D

Serine and valine

E Viruses that infect bacteria Question 14

Bacteriophages are

Options for Questions 15-15

E

DNA species that can enter cells and inhibit DNA replication

Question 15

Vectors are

Options for Questions 16-16

E Tyrosine and phenylalanine Question 16

Basic amino acids include

Options for Questions 17-17

E Tyrosine and tryptophan Question 17

Which amino acids contain an amide group?

Options for Questions 18-18 A Serine and valine

B

Arginine and lysine

C Glutamine and lysine

D

Histidine and proline

E Methionine and serine Question 18

Which amino acids are converted to cysteine in the human adult liver?

Options for Questions 19-19 A The smooth endoplasmic reticulum of fibroblasts

B

The smooth endoplasmic reticulum of myocytes

C The rough endoplasmic reticulum of fibroblasts

D

The rough endoplasmic reticulum of myocytes

A Cysteine

B

Methionine

C Valine

D

Proline

E The lysosomes of fibroblasts Question 19

Collagen is synthesised mainly in

Options for Questions 20-20

E Hydroxy-proline Question 20

The alpha chain of collagen has the basic structure Gly-A-B. One in three A residues are

Options for Questions 21-21 A Has two alpha chains

B

Has two identical and one different alpha chain

D

Has three different alpha chains and is found in skin

A There are 96 possible codons

B

Each codon has 4 bases

C Some codons recognise more than one amino acid

D

Some amino acids are recognised by more than one codon

C

Has three identical alpha chains and is found in the inter-vertebral disc

E Has three identical alpha chains and is found in skin Question 21

Type III collagen

Options for Questions 22-22

E Some codons have 5 bases Question 22

With respect to protein synthesis and the genetic code

Options for Questions 23-23 A The glomerulus

B

The proximal convoluted tubule

C The collecting ducts

D

The renal pelvis

E The descending limb of the loop of Henle

Question 23

With respect to the renal handling of urea, carrier-mediated secretion of urea into the tubular fluid occurs in

Options for Questions 24-24 A Have an aldose and a ketose group

B

Have an aldose but not a ketose group

C Have a ketose but not an aldose group

D

Have an aldose or a ketose group

A Lactose = glucose + fructose

B

Maltose = glucose + galactose

C Sucrose = glucose + fructose

D

Maltose = glucose + fructose

E May not have an aldose or a ketose group Question 24

Monosaccharides

Options for Questions 25-25

E Lactose = glucose + glucose Question 25

With respect to the structure of disaccharides

Options for Questions 26-26 A Triglycerides

B

Cholesterol

C Apoproteins

D

Phospholipids

E Glycogen Question 26

Which one is not typically found in lipoproteins?

Options for Questions 27-27 A Chylomicrons are denser than HDL

B

C HDL caries phospholipids and cholesterol to the liver D E

VLDL carries triglycerides from cells to the liver There is an association between high levels of HDL and atherosclerosis

High levels of LDL are known to protect against atherosclerosis

Question 27

With respect to lipoproteins

Options for Questions 28-28 A 0.01 g/ml

B

0.05 g/ml

C 0.1 g/ml

D

0.5 g/ml

E 1.0 g/ml Question 28

The density of LDL is around

Options for Questions 29-29 A

Is an oligosaccharide containing glucose and galactose

B

C Is a polysaccharide containing glucose and galactose D E

Is a branched chain polysaccharide containing glucose Is not stored in skeletal muscle

Is a branched chain polysaccharide containing glucose and lactose

Question 29

Glycogen

Options for Questions 30-30 A

Liver glycogen is converted to glucose-6-phosphate B for use by other tissues

Skeletal muscle and kidneys lack glucose-6phosphatase

C

The gut, skeletal muscle and kidneys cannot convert D glycogen to glucose

Skeletal muscle glycogen is converted to glucose-6phosphate which is used for glycolysis

E

Liver glycogen cannot be used for glycolysis in the liver

Question 30

During glycogenolysis

Options for Questions 31-31 A Glucose-1-phosphate

B

Glucose-6-phosphate

C UDP-glucose

D

UTP-glucose

E AMP-glucose Question 31

The first step in glycogen synthesis is the conversion of glucose to

Options for Questions 32-32 A Occurs in the mitochondria

B

Occurs in the cytoplasm

C Requires oxygen

D

Does not occur in red blood cells

E

Results in the consumption of one molecule of ATP per glucose molecule

Question 32

Glycolysis

Options for Questions 33-33

A The liver and skeletal muscle

B

The liver, gut and skeletal muscle

C The liver, renal cortex and skeletal muscle

D

The liver and renal cortex

A Free fatty acids

B

Oxaloacetate

C Lactate

D

Pyruvate

E Skeletal muscle and renal cortex Question 33

Gluconeogenesis occurs in

Options for Questions 34-34

E Glycerol Question 34

Which one is not a substrate for gluconeogenesis?

Options for Questions 35-35 A Pyruvate is converted to glucose in skeletal muscle

B

Pyruvate is converted to lactic acid by the liver

C NAD+ is converted to NADH in skeletal muscle

D

Lactate is converted to glucose by the liver

A Results in the release of carbon monoxide

B

Is mediated by the enzyme fatty acylCoA

C Results in the generation of ATP

D

Is mediated by fatty acid synthase

A The cytoplasm

B

The lysosomes

C The golgi apparatus

D

The smooth endoplasmic reticulum

E Glucose is converted to lactate by the liver Question 35

During the Cori cycle

Options for Questions 36-36

E

Occurs by the repetitive addition of two carbon units from glycerol

Question 36

Fatty acid synthesis

Options for Questions 37-37

E The rough endoplasmic reticulum Question 37

The breakdown of triglycerides occurs in

Options for Questions 38-38 A Is catalysed by fatty acid synthase

B

Results in the generation of ATP

C Results in the hydrolysis of ATP to ADP

D

Results in the hydrolysis of ATP to AMP

E Occurs in the mitochondria Question 38

Fatty acid oxidation begins with the conversion of fatty acids to fatty Acyl CoA. This reaction

Options for Questions 39-39 A Can utilise ketone bodies as fuel

B

Only utilises glucose as fuel

C Can utilise glucose and ketone bodies as fuel

D

Only utilises ketone bodies as fuel

A Glucose

B

Ribose

C Glucose-1-phosphate

D

Ribose-6-phosphate

E

Can utilise ketone bodies as fuel if the woman has type 1 diabetes

Question 39

The fetal brain

Options for Questions 40-40

E Glucose-6-phosphate Question 40

The starting substrate for the pentose phosphate pathway is

Options for Questions 41-41 A 6 ATP and 6 GTP

B

12 ATP and 12 GTP

C 12 ATP and 1 GTP

D

3 ATP and 1 GTP

E 4 ATP and 2 GTP Question 41

Each turn of the citric (tri-carboxylic) acid cycle produces

Options for Questions 42-42 A Pyruvate dehydrogenase

B

Hormone-sensitive lipase

C Phosphofructokinase

D

Pyruvate kinase

E Lactate dehydrogenase Question 42

Thiamine phosphate is a prosthetic group for which enzyme?

Options for Questions 43-43 A Fatty acids

B

Glucose

C Amino acids

D

Porphyrin

E Folic acid Question 43

Which one is not a product of intermediate molecules derived from the citric acid cycle?

Options for Questions 44-44 A

The enzyme concentration at which the initial velocity is half of Vmax

B

The initial velocity at t = 0.5

C

The substrate concentration at which the initial velocity is half of Vmax

D

The enzyme concentration at which the initial velocity is proportional to the substrate concentration

E

The substrate concentration at which the initial velocity is equal to Vmax

Question 44

With respect to enzyme kinetics, the Michaelis constant is

Options for Questions 45-45 A A rectangular hyperbola

B

The Michaelis-Menten plot

C The Lineweaver-Burk plot

D

Intercepts the x-axis at Vmax

E Has a slopw = Km Question 45

With respect to enzyme kinetics, a graph plotting 1/V0 against 1/[S] is

Options for Questions 46-46 A Cause an apparent increase in the Km of the enzyme B

Cannot be converted to product by the enzyme

C Cause a reduction in the Vmax of the enzyme

Result in the Km of the enzyme being unchanged

E

D

Can result in an apparent increase in the Vmax of the enzyme

Question 46

The activity of enzymes can be influenced by competitive inhibitors. Competitive inhibitors

Options for Questions 47-47 A Are proteins or polypeptides

B

Bind to enzymes and convert them to apo-enzymes

C Can be co-enzymes or prosthetic groups

D

Are always bound to the enzyme by covalent bonds

E

Are always bound to the enzyme by non-covalent bonds

Question 47

Enzyme cofactors

Options for Questions 48-48 A Hydrolyses peptide bonds

B

Converts pepsinogen to pepsin

C Hydrolyses glycosidic bonds

D

Hydrolyses triglycerides to free fatty acids and glycerol

A Occurs in the mouth, stomach and small intestines

B

Occurs in the stomach and small intestines only

C Does not occur in the stomach

D

Is undertaken by amylase and pepsin

E Is most active in an acidic environment Question 48

Salivary amylase

Options for Questions 49-49

E Is undertaken by pepsinogen and trypsinogen Question 49

Enzymatic digestion of carbohydrates

Options for Questions 50-50 A Adenine

B

Uracil

C Cytosine

D

Guanine

E Thymine Question 50

Nitrogenous bases make up cellular nucleic acids including DNA and RNA. Which of these nitrogen bases is found in RNA but not in DNA?

20 random questions for Best of 5 Test Options for Questions 1-1 A Alanine

B

Arginine

C Taurine

D

Serine

E Tyrosine

Question 1 Which one is an aromatic amino acid?

Options for Questions 2-2

A Arginine and lysine

B

Aspartate and glutamate

C Alanine and valine

D

Taurine and methionine

A Leucine and arginine

B

Alanine and arginine

C Serine and valine

D

Methionine and cysteine

E Glutamine and cysteine

Question 2 Aliphatic amino acids include

Options for Questions 3-3

E Leucine and lysine

Question 3 Strictly ketogenic amino acids include

Options for Questions 4-4 A Alanine and valine

B

Leucine and lysine

C Tyrosine and alanine

D

Phenylalanine and lysine

E Arginine and lysine

Question 4 Strictly glucogenic amino acids include

Options for Questions 5-5 A Cysteine

B

Methionine

C Valine

D

Proline

E Hydroxy-proline

Question 5

The alpha chain of collagen has the basic structure Gly-A-B. One in three B residues are

Options for Questions 6-6 A

Collagen fibrils are visible under the light microscope

B

Collagen fibrils have a banded appearance on electron microscopy

C

Collagen fibres are not visible under the light microscope

D

Collagen fibres aggregate to form collagen fibrils

E All collagen fibrils have a double helix structure

Question 6 With respect to the structure of collagen

Options for Questions 7-7 A Type I

B

Type II

C Type III

D

Type IV

E Type V

Question 7

Which one is the predominant type of collagen found in basement membranes?

Options for Questions 8-8 A Has two alpha chains

B

Has three different alpha chains

C Is mainly found in skin and bone

D

Has two identical and one different alpha chain

A Occurs by transcription in the ribosomes

B

Occurs by translation in the nucleus

C Occurs by transcription within the cytoplasm

D

Does not occur in the rough endoplasmic reticulum

A 2 bases

B

3 bases

C 4 bases

D

3 or 4 bases

E Is the main type of collagen in skin Question 8 Type IV collagen

Options for Questions 9-9

E Occurs by translation in ribosomes

Question 9 Protein synthesis

Options for Questions 10-10

E 3 base pairs Question 10

Proteins are synthesised from amino acids using the genetic code. Each codon is made up of

Options for Questions 11-11 A There are 96 possible codons

B

Each codon has 4 bases

C Some codons recognise more than one amino acid

D

Some amino acids are recognised by more than one codon

E Some codons have 5 bases Question 11

With respect to protein synthesis and the genetic code

Options for Questions 12-12 A There are 5 different enzymes

B

The reaction catalysed results in ATP production

C There are 20 different enzymes

D

The reaction catalysed results in the formation of disulphide bonds

E

There are 3 different enzymes – alpha, beta and gamma

Question 12

Aminoacyl tRNA synthetase plays a key role in protein synthesis.

Options for Questions 13-13 A

The pairing between codon and anti-codon is more stringent than the pairing between DNA base pairs

B

Pairing will not occur if the third position on the C mRNA codon read from the 5- to 3- end and the first D position on the anticodon are not an exact match

Pairing will only occur if the third position on the mRNA codon read from the 5- to 3- end and the first position on the anticodon are an exact match Pairing will only occur if all bases on the mRNA codon and the tRNA anti-codon are an exact match

Pairing may still occur when the third position on the E mRNA codon read from the 5- to 3- end and the first position on the anticodon is not an exact match Question 13

The genetic code is central to protein synthesis. This requires pairing between the codon and the anti-codon

Options for Questions 14-14 A TTT

B

GAU

C AUG or GAU

D

AUG

E AUG or TTT Question 14

During protein synthesis, the start codon is

Options for Questions 15-15 A Elongation is catalysed by peptidyl transferase

B

C

Once the peptide bond is formed, there is a checking D mechanism to remove wrong amino acids

E

The polypeptide chain is synthesised from C- to Nterminal

Question 15

New amino acids are added at the P site of the ribosome The termination codon is AUG

During protein synthesis

Options for Questions 16-16 A AUG

B

TTT

C UAA

D

UTT

E GUT Question 16

With respect to protein synthesis, which one is a stop codon?

Options for Questions 17-17 A Gout

B

Pre-renal renal failure

C Low dose aspirin

D

Diabetic keto-acidosis

E Corticosteroid therapy Question 17

Which one is not associated with raised plasma uric acid levels?

Options for Questions 18-18 A The spleen

B

The kidneys

C The liver

D

The reticulo-endothelial system

A During pregnancy

B

By insulin

C By consuming a high protein diet

D

By testosterone

A Smooth endoplasmic reticulum

B

Rough endoplasmic reticulum

C Lysosomes

D

Ribosomes

E Red blood cells Question 18

The urea cycle occurs in

Options for Questions 19-19

E By growth hormone Question 19

Urea excretion is increased

Options for Questions 20-20

E Nucleolus Question 20

Which intracellular organelle processes, packages and transports proteins out of the cell?

50 random questions for Best of 5 Test Options for Questions 1-1 A Nucleotides linked by 3-5-phosphodiester bonds

B

Ribose linked to deoxyribose by hydrogen bonds

C Nucleotides linked to ribose or deoxyribose

D

Purine bases linked to pyrimidine bases by hydrogen bonds

A Are highly acidic proteins

B

Are negatively charged proteins

C Are rich in arginine and lysine

D

Are rich in valine and alanine

A Histone octamers

B

Histone dimers

C Histone tetramers

D

Chromatin

E

Purine bases linked to ribose sugars by 3-5phosphodiester bonds

Question 1 Nucleic acids are formed from

Options for Questions 2-2

E

Interact with the positively charged ribose group on the DNA molecule

Question 2 Histones

Options for Questions 3-3

E Spindle fibres

Question 3 To form nucleosomes, DNA is wrapped around

Options for Questions 4-4 A Has a 3-methylated cap

B

Has a 5-poly-A tail

C Has a start codon AUG

D

Has a sequence that is written in the 3- to 5- direction

B

There is base-paring within mRNA but not rRNA

D

mRNA does not have a poly-A tail while rRNA has a poly-A tail

E Contains the base Thymine

Question 4 Messenger RNA

Options for Questions 5-5 A mRNA is more stable than rRNA C

mRNA does not have a secondary structure while rRNA has a secondary structure

E mRNA is 80S in size while rRNA is 40S or 60S

Question 5 With respect to the differences between mRNA and rRNA

Options for Questions 6-6 A 5% of total cellular RNA

B

15% of total cellular RNA

C 35% of total cellular RNA

D

55% of total cellular RNA

A DNA

B

rRNA

C tRNA

D

mRNA

E 85% of total cellular RNA

Question 6 Transfer RNA makes up

Options for Questions 7-7

E tRNA bound to mRNA Question 7 Which nucleic acid has a clover-leaf secondary structure?

Options for Questions 8-8 A DNA polymerase recognizes promoter regions

B

Promoter regions are located downstream of the start site

C There are no specific stop codons

D

The RNA chain elongates in the 3- to 5- direction

A That begins with 5-GU

B

That ends in 5-GU

C That begins with 3-AG

D

That begins with 5-AG

A Addition of 3-poly-A tail

B

Addition of 5-methylated cap

C Addition of exons

D

Removal of introns

E

Transcription factors bind transfer RNA to amino acids

Question 8 During transcription

Options for Questions 9-9

E That ends with 3-GU Question 9 Introns have a sequence

Options for Questions 10-10

E Amino acid binding

Question 10

With respect to transcription, which process occurs in spliceosomes?

Options for Questions 11-11 A The cell is haploid in the G2 phase

B

The cell is diploid in the G2 phase

C The cell is tetraploid in the G2 phase

D

DNA synthesis occurs in the G1 phase

A Occurs in the M phase of the cell cycle

B

Is semi-conservative and uni-directional

C Is semi-conservative and bi-directional

D

Occurs in ribosomes

B

DNA polymerase alpha – repairs DNA

E DNA synthesis occurs in the M phase Question 11

During the cell cycle

Options for Questions 12-12

E

Results in the production of a DNA molecule with two new strands

Question 12

DNA replication

Options for Questions 13-13 A

DNA polymerase alpha – synthesizes the lagging strand of DNA

C

DNA polymerase gamma – synthesizes the leading D strand of DNA

DNA polymerase delta – produces Okazaki fragments

E DNA polymerase beta – replicated DNA at telomeres Question 13

With respect to the action of DNA polymerases

Options for Questions 14-14 A ATATAT

B

AAATTT

C AATAAT

D

ATTATT

E AATTAA Question 14

Which one is a palindromic sequence?

Options for Questions 15-15 A DNA ligase

B

DNA helicase

C DNA polymerases

D

Telomerases

E Restriction endonucleases

Question 15

The polymerase chain reaction has been used to amplify a specific DNA sequence. In order to identify the amplified DNA, it needs to be cut into fragments of specific sizes. Which enzymes undertake this function?

Options for Questions 16-16 A Recognize specific amino acid sequences

B

Recognize specific proteins

C Recognize specific nucleotides

D

Recognize specific polysaccharides

A Arginine

B

Leucine

C Lysine

D

Tryptophan

E Recognize specific DNA sequences Question 16

Restriction endonucleases

Options for Questions 17-17

E Valine Question 17

Which one is not an essential amino acid?

Options for Questions 18-18 A Methionine, serine and taurine

B

Leucine, isoleucine and lysine

C Lysine, arginine and taurine

D

Methionine, phenylalanine and alanine

B

Secondary structure is the linear sequence of amino acids including disulphide bonds

D

Tertiary structure is dependent on covalent bonds

E Histidine, valine and tyrosine Question 18

Essential amino acids include

Options for Questions 19-19 A Haemoglobin does not have a quaternary structure C

Secondary structure includes folding into pleated sheets

E

Tertiary structure is only present in proteins with more than one sub-unit

Question 19

With respect to the structure of proteins

Options for Questions 20-20 A Endothelial cells

B

Fibroblasts

C Epithelial cells

D

Myocytes

A 3

B

20

C 23

D

64

E Phagocytes Question 20

Collagen is synthesised mainly by

Options for Questions 21-21

E 96 Question 21

With respect to the genetic code, how many different possible codons are there?

Options for Questions 22-22 A There are 96 possible codons

B

Each codon has 4 bases

C Some codons recognise more than one amino acid

D

Some amino acids are recognised by more than one codon

E Some codons have 5 bases Question 22

With respect to protein synthesis and the genetic code

Options for Questions 23-23 A AUG

B

TTT

C UAA

D

UTT

E GUT Question 23

With respect to protein synthesis, which one is a stop codon?

Options for Questions 24-24 A Uric acid

B

Urea

C Urate

D

Acetyl CoA

E Acetate Question 24

Which molecule has formula CO(NH2)2?

Options for Questions 25-25 A Is independent of anti-diuretic hormone

B

Increases at low urine flow rates

C Increases at high urine flow rates

D

Decreases at low urine flow rates

E Occurs by passive diffusion Question 25

Urea reabsorption in the medullary collecting ducts

Options for Questions 26-26 A Pregnancy

B

Insulin

C Corticosteroids

D

Growth hormone

E Testosterone Question 26

Which one is not associated with decreased urea excretion?

Options for Questions 27-27 A Have an aldose and a ketose group

B

Have an aldose but not a ketose group

C Have a ketose but not an aldose group

D

Have an aldose or a ketose group

A Fatty acids

B

Glycocholate or taurocholate

C Phospholipids

D

Bile pigment

E May not have an aldose or a ketose group Question 27

Monosaccharides

Options for Questions 28-28

E Bilirubin Question 28

Cholesterol is excreted in bile as

Options for Questions 29-29 A

Three identical fatty acid chains esterified to a glycerol backbone

B

Three fatty acid chains esterified to a galactose backbone

C

Three fatty acid chains esterified to a glycerol backbone

D

Three glycerol molecules esterified to a fatty acid chain

E

Three galactose molecules esterified to a fatty acid chain

Question 29

Triglycerides are composed of

Options for Questions 30-30 A Three identical fatty acid chains

B

Three glycerol molecules

C Unsaturated fatty acid chains

D

Saturated fatty acid chains

A Triglycerides

B

Cholesterol

C Apoproteins

D

Phospholipids

E Only one fatty acid chain Question 30

Simple triglycerides have

Options for Questions 31-31

E Glycogen Question 31

Which one is not typically found in lipoproteins?

Options for Questions 32-32 A Are the smallest types of lipoprotein

B

Are the most dense lipoprotein

C Have a mass of about 400kDa

D

Have a protein content of 15-20%

A All glucose units

B

Glucose units up to 4 residues from a branch point

C Glucose units up to 3 residues from a branch point

D

Glucose units up to 2 residues from a branch point

E Have a density of about 0.095 g/ml Question 32

Chylomicrons

Options for Questions 33-33

E Glucose units up to the branch point Question 33

During glycogenolysis, phosphorylase removes

Options for Questions 34-34 A Removal of glucose units from glycogen

B

Addition of glucose units from glucose-1-phosphate to glycogen

C

Addition of glucose units from glucose-6-phosphate D to glycogen

E

Addition of glucose units from UMP-glucose to glycogen

Question 34

Addition of glucose units from UDP-glucose to glycogen

Which reaction is catalysed by the enzyme glycogen synthase?

Options for Questions 35-35 A

Insulin stimulates the activation of protein phosphatase I

C Insulin stimulates glycogenolysis E

B

Insulin inhibits the phosphorylation of protein phosphatase I

D

Insulin inhibits glycogen synthesis

Insulin stimulates the conversion of skeletal muscle glycogen to glucose

Question 35

With respect to the regulation of glycogen metabolism

Options for Questions 36-36 A One

B

Two

C Three

D

Four

E Two or three depending on oxygen levels Question 36

How many molecules of ATP are generated per glucose molecule during glycolysis?

Options for Questions 37-37 A Other carbohydrates

B

Free fatty acids

C Non-carbohydrate precursors

D

Amino acids

E Lactate Question 37

Gluconeogenesis is the formation of glucose from

Options for Questions 38-38 A Is catalysed by fatty acid synthase

B

Results in the generation of ATP

C Results in the hydrolysis of ATP to ADP

D

Results in the hydrolysis of ATP to AMP

E Occurs in the mitochondria Question 38

Fatty acid oxidation begins with the conversion of fatty acids to fatty Acyl CoA. This reaction

Options for Questions 39-39

B

Shuttling of fatty acyl CoA requires the presence of folic acid

D

Ketone bodies are consumed

A Can utilise ketone bodies as fuel

B

Only utilises glucose as fuel

C Can utilise glucose and ketone bodies as fuel

D

Only utilises ketone bodies as fuel

A Insulin concentrations rise

B

Glucagon concentrations fall

C Glycogen synthesis is stimulated

D

Glycogenolysis is stimulated

A

Fatty acyl CoA is carried to the cytoplasm for beta oxidation

C Carnitine is required for fatty acyl CoA shuttling E Cyclic GMP is generated Question 39

During fatty acid oxidation

Options for Questions 40-40

E

Can utilise ketone bodies as fuel if the woman has type 1 diabetes

Question 40

The fetal brain

Options for Questions 41-41

E Triglyceride breakdown is inhibited Question 41

During the post-absorptive phase of starvation

Options for Questions 42-42 A Glycolysis is stimulated

B

Fatty acid oxidation is inhibited in the liver

C Amino acids are released from skeletal muscle

D

Amino acids are utilised by skeletal muscle for glucose synthesis

E Phosphofructokinase is activated Question 42

In the gluconeogenic phase of starvation

Options for Questions 43-43 A Glucose

B

Ribose

C Glucose-1-phosphate

D

Ribose-6-phosphate

E Glucose-6-phosphate Question 43

The starting substrate for the pentose phosphate pathway is

Options for Questions 44-44 A NAD+ only

B

NAD+ and FAD only

C NAD+, FAD and fatty acids

D

NAD+, FAD and CoA

E FAD only Question 44

Ribose-5-phosphate is a precursor for the synthesis of

Options for Questions 45-45 A Svedberg units

B

MicroM per second

C Katal

D

Michaelis units

A A rectangular hyperbola

B

The Michaelis-Menten plot

C The Lineweaver-Burk plot

D

Intercepts the x-axis at Vmax

E Kilo Joules Question 45

The SI unit for enzyme activity is

Options for Questions 46-46

E Has a slopw = Km Question 46

With respect to enzyme kinetics, a graph plotting 1/V0 against 1/[S] is

Options for Questions 47-47 A Are proteins or polypeptides

B

Bind to enzymes and convert them to apo-enzymes

C Can be co-enzymes or prosthetic groups

D

Are always bound to the enzyme by covalent bonds

A Increase the Vmax of the enzyme

B

Reduce the Km of the enzyme

C Bind to the enzyme by covalent bonds

D

Convert the enzyme into an apo-enzyme

E

Are always bound to the enzyme by non-covalent bonds

Question 47

Enzyme cofactors

Options for Questions 48-48

E Are types of co-enzyme Question 48

Enzyme prosthetic groups

Options for Questions 49-49 A Sucrase converts sucrose to glucose and galactose

B

Lactase converts lactose to glucose and fructose

C Maltase converts maltose to glucose and fructose

D

Sucrase converts sucrose to glucose and fructose

E Maltase converts maltose to glucose and galactose Question 49

During the digestion of carbohydrates

Options for Questions 50-50 A Smooth endoplasmic reticulum

B

Rough endoplasmic reticulum

C Lysosomes

D

Ribosomes

E Nucleolus Question 50

Which intracellular organelle processes, packages and transports proteins out of the cell?

50 random questions for Best of 5 Test Options for Questions 1-1 A Have 6 carbon atoms

B

Have either 5 or 6 carbon atoms

C Have 5 carbon atoms

D

Include maltose

E Include pyrimidine

Question 1 With respect to the structure of nucleic acids, the sugar molecules

Options for Questions 2-2 A 5% of total cellular RNA

B

15% of total cellular RNA

C 35% of total cellular RNA

D

55% of total cellular RNA

A A primer is required for mRNA synthesis

B

Both the sense and the anti-sense DNA strands are transcribed

C Only the sense DNA strand is transcribed

D

The mRNA is synthesized in the 5- to 3- direction

E 85% of total cellular RNA

Question 2 Transfer RNA makes up

Options for Questions 3-3

E Any incorrect bases are removed by nucleases

Question 3 During transcription

Options for Questions 4-4 A Addition of exons

B

Removal of exons

C Addition of introns

D

Removal of introns

E Conversion of introns into exons

Question 4 Post-transcriptional mRNA processing includes

Options for Questions 5-5 A Occurs when some introns are not spliced

B

Occurs when some exons are spliced

C Is part of RNA editing

D

Results in addition or substitution of nucleotides

A Is called transcription

B

Is called translation

C Requires the presence of primers

D

Requires the presence of ribonucleotides

A Recognize specific amino acid sequences

B

Recognize specific proteins

C Recognize specific nucleotides

D

Recognize specific polysaccharides

B

White blood cells that have ingested bacteria

E Does not occur in eukaryotic cells

Question 5 Alternative splicing of mRNA

Options for Questions 6-6

E Is catalyzed by DNA polymerase Question 6 The synthesis of DNA from RNA

Options for Questions 7-7

E Recognize specific DNA sequences

Question 7 Restriction endonucleases

Options for Questions 8-8 A Bacteria that have ingested white blood cells

C Bacteria that have been infected by viruses

D

Bacteria that can be infected by viruses

A Fragments of DNA outside cells

B

Fragments of RNA outside cells

C DNA species that can replicate outside cells

D

DNA species that can enter cells and replicate within them

A Methionine, serine and taurine

B

Leucine, isoleucine and lysine

C Lysine, arginine and taurine

D

Methionine, phenylalanine and alanine

A Alanine and arginine

B

Arginine and lysine

C Methionine and serine

D

Glutamine and aspartate

A Endothelial cells

B

Fibroblasts

C Epithelial cells

D

Myocytes

E Viruses that infect bacteria Question 8 Bacteriophages are

Options for Questions 9-9

E

DNA species that can enter cells and inhibit DNA replication

Question 9 Vectors are

Options for Questions 10-10

E Histidine, valine and tyrosine Question 10

Essential amino acids include

Options for Questions 11-11

E Tyrosine and phenylalanine Question 11

Basic amino acids include

Options for Questions 12-12

E Phagocytes Question 12

Collagen is synthesised mainly by

Options for Questions 13-13

A Three alpha chains

B

Five alpha chains

C One alpha and two beta chains

D

Two alpha and one beta chain

A Initiation

B

Transcription

C Elongation

D

Translocation

E Two alpha and two beta chains Question 13

Collagen fibrils contain

Options for Questions 14-14

E Termination Question 14

Which one is not a recognised stage during protein synthesis from mRNA?

Options for Questions 15-15 A There are 96 possible codons

B

Each codon has 4 bases

C Some codons recognise more than one amino acid

D

Some amino acids are recognised by more than one codon

E Some codons have 5 bases Question 15

With respect to protein synthesis and the genetic code

Options for Questions 16-16 A

The pairing between codon and anti-codon is more stringent than the pairing between DNA base pairs

B

Pairing will not occur if the third position on the C mRNA codon read from the 5- to 3- end and the first D position on the anticodon are not an exact match

Pairing will only occur if the third position on the mRNA codon read from the 5- to 3- end and the first position on the anticodon are an exact match Pairing will only occur if all bases on the mRNA codon and the tRNA anti-codon are an exact match

Pairing may still occur when the third position on the E mRNA codon read from the 5- to 3- end and the first position on the anticodon is not an exact match Question 16

The genetic code is central to protein synthesis. This requires pairing between the codon and the anti-codon

Options for Questions 17-17 A TTT

B

GAU

C AUG or GAU

D

AUG

E AUG or TTT

Question 17

During protein synthesis, the start codon is

Options for Questions 18-18 A Gout

B

Pre-renal renal failure

C Low dose aspirin

D

Diabetic keto-acidosis

E Corticosteroid therapy Question 18

Which one is not associated with raised plasma uric acid levels?

Options for Questions 19-19 A 2 or 3

B

3 or more

C 5 or 6

D

3, 6 or 9

E 2, 4 or 6 Question 19

Monosaccharides have a formula (CH2O)n where n is

Options for Questions 20-20 A Mainly excreted by the kidneys

B

Mainly synthesised from triglycerides

C Mainly synthesised from phospholipids

D

Synthesised from acetyl CoA

E Mainly excreted as cholesterol phosphate Question 20

With respect to cholesterol metabolism, cholesterol is

Options for Questions 21-21 A Fatty acids

B

Glycocholate or taurocholate

C Phospholipids

D

Bile pigment

A Are synthesised by the liver

B

Are synthesised in the portal circulation

C Transport cholesterol from the liver

D

Transport dietary lipids to tissues

E Bilirubin Question 21

Cholesterol is excreted in bile as

Options for Questions 22-22

E Are not present in the peripheral circulation Question 22

Chylomicrons

Options for Questions 23-23 A Are the smallest types of lipoprotein

B

Are the most dense lipoprotein

C Have a mass of about 400kDa

D

Have a protein content of 15-20%

A Is synthesised by adipose tissue

B

Has a molecular weight of about 400 kDa

C Has a density of less than 1 g / ml

D

Transports lipids from the liver to other tissues

E Have a density of about 0.095 g/ml Question 23

Chylomicrons

Options for Questions 24-24

E Transports lipids from the gut to the liver Question 24

Very low density lipoprotein (VLDL)

Options for Questions 25-25 A

Skeletal muscle glycogen is used to maintain blood B glucose levels

C Liver glycogen is stored in the lysosomes E

D

Liver, but not skeletal muscle glycogen is used to maintain blood glucose levels Liver glycogen is stored in the endoplasmic reticulum

Glycogen is stored in granules within the cell membrane

Question 25

With respect to glycogen metabolism

Options for Questions 26-26 A

Liver glycogen is converted to glucose-6-phosphate B for use by other tissues

Skeletal muscle and kidneys lack glucose-6phosphatase

C

The gut, skeletal muscle and kidneys cannot convert D glycogen to glucose

Skeletal muscle glycogen is converted to glucose-6phosphate which is used for glycolysis

E

Liver glycogen cannot be used for glycolysis in the liver

Question 26

During glycogenolysis

Options for Questions 27-27

A

Phosphorylase exists as an active (beta) form and an B inactive (delta) form

The phosphorylated form of phosphorylase is inactive

C

The phosphorylated form of glycogen synthase is inactive

The de-phosphorylated form of phosphorylase is active

E

The phosphorylated form of glycogen synthase is active

Question 27

D

Glycogen metabolism is partly regulated by the activity of phosphorylase and glycogen synthase

Options for Questions 28-28 A

Insulin stimulates the activation of protein phosphatase I

C Insulin stimulates glycogenolysis E

B

Insulin inhibits the phosphorylation of protein phosphatase I

D

Insulin inhibits glycogen synthesis

Insulin stimulates the conversion of skeletal muscle glycogen to glucose

Question 28

With respect to the regulation of glycogen metabolism

Options for Questions 29-29 A Free fatty acids

B

Oxaloacetate

C Lactate

D

Pyruvate

E Glycerol Question 29

Which one is not a substrate for gluconeogenesis?

Options for Questions 30-30 A Results in the release of carbon monoxide

B

Is mediated by the enzyme fatty acylCoA

C Results in the generation of ATP

D

Is mediated by fatty acid synthase

A Is mediated by fatty acylCoA synthase

B

Is mediated by hormone sensitive lipase

C Is inhibited by glucagon

D

Is activated by insulin

E

Occurs by the repetitive addition of two carbon units from glycerol

Question 30

Fatty acid synthesis

Options for Questions 31-31

E

Results in the production of glycerol which cannot be used in the glycolysis pathway

Question 31

The breakdown of triglycerides

Options for Questions 32-32 A Occurs exclusively in the cytoplasm

B

Occurs exclusively in the mitochondria

D

Begins in the mitochondria and continues in the cytoplasm

A Acetyl CoA

B

Malonyl CoA

C Oxaloacetate

D

Lactate

C

Begins in the cytoplasm and continues in the mitochondria

E Results in the production of glycerol Question 32

Fatty acid oxidation

Options for Questions 33-33

E Glycerol Question 33

During beta oxidation, ketone bodies are produced from

Options for Questions 34-34 A Are produced mainly by skeletal muscle

B

Are metabolised mainly by the brain

C Can be used as fuel by the heart and renal cortex

D

Are the main fuel used by the brain during exercise

A Ketone bodies inhibit insulin secretion

B

Insulin secretion is increased

C Acetoacetate is converted to acetyl CoA

D

The liver uses ketone bodies as fuel

E

Are the main fuel used by the renal medulla and the adrenal gland

Question 34

Ketone bodies

Options for Questions 35-35

E Protein hydrolysis is accelerated Question 35

During the ketotic phase of starvation

Options for Questions 36-36 A Glucose

B

Ribose

C Glucose-1-phosphate

D

Ribose-6-phosphate

E Glucose-6-phosphate

Question 36

The starting substrate for the pentose phosphate pathway is

Options for Questions 37-37 A

Has a phosphorylated and a de-phosphorylated pathway

B

Has an oxidative and a non-oxidative pathway

D

Has an alpha-glycolytic and a beta-glycolytic pathway

A NAD+ only

B

NAD+ and FAD only

C NAD+, FAD and fatty acids

D

NAD+, FAD and CoA

C Has a cytosolic and a mitochondrial component E Occurs in the nucleus Question 37

The pentose phosphate pathway

Options for Questions 38-38

E FAD only Question 38

Ribose-5-phosphate is a precursor for the synthesis of

Options for Questions 39-39 A The nucleus

B

The mitochondria

C The mitochondria and cytoplasm

D

The lysosomes

E The cytoplasm Question 39

The pentose phosphate pathway occurs in

Options for Questions 40-40 A Resulta in the oxidation of glucose to CO2 and water B

Cannot utilise acetyl CoA

C Begins in the cytosol

Occurs in mitochondria

D

E Can occur under anaerobic conditions Question 40

The citric acid (tri-carboxylic acid) cycle

Options for Questions 41-41 A Pyruvate dehydrogenase

B

Hormone-sensitive lipase

C Phosphofructokinase

D

Pyruvate kinase

E Lactate dehydrogenase Question 41

Thiamine phosphate is a prosthetic group for which enzyme?

Options for Questions 42-42 A A molecule that increases the rate of the reaction

B

C A molecule that modifies the activity of the enzyme D E

A molecule that increases the rate at which equilibrium is reached A molecule that alters the product of the reaction

A molecule that reduces the rate at which equilibrium is reached

Question 42

With respect to the properties of enzymes, a cofactor is

Options for Questions 43-43 A Increase the Vmax of the enzyme

B

Reduce the Km of the enzyme

C Bind to the enzyme by covalent bonds

D

Convert the enzyme into an apo-enzyme

A Hydrolyses peptide bonds

B

Converts pepsinogen to pepsin

C Hydrolyses glycosidic bonds

D

Hydrolyses triglycerides to free fatty acids and glycerol

A Occurs in the mouth, stomach and small intestines

B

Occurs in the stomach and small intestines only

C Does not occur in the stomach

D

Is undertaken by amylase and pepsin

E Are types of co-enzyme Question 43

Enzyme prosthetic groups

Options for Questions 44-44

E Is most active in an acidic environment Question 44

Salivary amylase

Options for Questions 45-45

E Is undertaken by pepsinogen and trypsinogen Question 45

Enzymatic digestion of carbohydrates

Options for Questions 46-46

A Begins in the mouth

B

Does not occur in the stomach

C Is undertaken by amylase and lipase

D

Occurs in the mouth and stomach

A Phospholipids

B

Polysaccharides

C Positively charged proteins

D

Negatively charged proteins

E Begins in the stomach Question 46

The digestion of lipids

Options for Questions 47-47

E Arachidonic acid derivatives Question 47

What type of compound is Histones?

Options for Questions 48-48 A DNA repair

B

DNA synthesis

C Unwinding of the double helix

D

DNA breakdown

E Ligation of DNA fragments Question 48

What is the function of DNA polymerase?

Options for Questions 49-49 A Adenine

B

Uracil

C Cytosine

D

Guanine

E Thymine Question 49

Nitrogenous bases make up cellular nucleic acids including DNA and RNA. Which of these nitrogen bases is found in RNA but not in DNA?

Options for Questions 50-50 A Inhibition of mitochondrial function

B

Binding to folic acid receptor

C Ectopic induction of gene expression

D

Vaso-constriction in limb bud arteries

E Induction of prostaglandin E2 synthesis Question 50

What is the pathophysiological mechanism by which vitamin A excess can cause congenital anomalies?

0 random questions for Best of 5 Test Options for Questions 1-1 A Arginine

B

Leucine

C Lysine

D

Tryptophan

E Valine

Question 1 Which one is not an essential amino acid?

Options for Questions 2-2 A Alanine

B

Arginine

C Taurine

D

Serine

E Tyrosine

Question 2 Which one is an aromatic amino acid?

Options for Questions 3-3 A Methionine and glutamine

B

Taurine and valine

C Serine and arginine

D

Methionine and taurine

E Leucine and alanine

Question 3 Sulphur-containing amino acids include

Options for Questions 4-4 A Glutamine and asparagine

B

Glutamine and glutamate

C Arginine and methionine

D

Serine and valine

E Tyrosine and tryptophan Question 4 Which amino acids contain an amide group?

Options for Questions 5-5 A Stored in ribosomes

B

Stored in the liver

C Excreted in urine

D

Excreted in bile

E Converted to glucose or fatty acids

Question 5 With respect to amino acid metabolism, excess amino acids are

Options for Questions 6-6 A Lysine and leucine

B

Lysine and arginine

C Tyrosine and phenylalanine

D

Tryptophan and leucine

E Lysine and isoleucine

Question 6

Amino acids that can be converted to glucose and ketone bodies include

Options for Questions 7-7 A Alanine and valine

B

Leucine and lysine

C Tyrosine and alanine

D

Phenylalanine and lysine

E Arginine and lysine

Question 7 Strictly glucogenic amino acids include

Options for Questions 8-8 By facilitated diffusion in the distal convoluted tubule

B

By active transport in the proximal convoluted tubule

C By diffusion in the proximal convoluted tubule

D

By active transport in the loop of Henle

A

E By facilitated diffusion in the loop of Henle

Question 8

Amino acids are small molecules which are filtered in the glomerulus. The amino acids are than absorbed

Options for Questions 9-9 A Endothelial cells

B

Fibroblasts

C Epithelial cells

D

Myocytes

B

The smooth endoplasmic reticulum of myocytes

E Phagocytes Question 9 Collagen is synthesised mainly by

Options for Questions 10-10 A The smooth endoplasmic reticulum of fibroblasts

C The rough endoplasmic reticulum of fibroblasts

D

The rough endoplasmic reticulum of myocytes

A Cysteine

B

Methionine

C Valine

D

Proline

E The lysosomes of fibroblasts Question 10

Collagen is synthesised mainly in

Options for Questions 11-11

E Hydroxy-proline Question 11

The alpha chain of collagen has the basic structure Gly-A-B. One in three B residues are

Options for Questions 12-12 A Occurs by transcription in the ribosomes

B

Occurs by translation in the nucleus

C Occurs by transcription within the cytoplasm

D

Does not occur in the rough endoplasmic reticulum

B

One protein can be coded for by more than one gene

C One codon can recognise more than one amino acid D

One amino acid can be recognised by more than one codon

E Occurs by translation in ribosomes Question 12

Protein synthesis

Options for Questions 13-13 A One gene can code for more than one protein

E One codon can have different number of bases Question 13

The genetic code is degenerate. This means that

Options for Questions 14-14 A TTT

B

GAU

C AUG or GAU

D

AUG

E AUG or TTT Question 14

During protein synthesis, the start codon is

Options for Questions 15-15

A Are only present in hormones

B

Play an important role in cell signaling

C Target the proteins to specific sites within the cell

D

Are only present in proteins destined for export into the extra-cellular space

E Are removed in the ribosomes Question 15

Post-translational modification of proteins include excision of signal sequences. Signal sequences

Options for Questions 16-16 A 50% of circulating urate is bound to albumin C

B

One third of daily uric acid production is excreted in D faeces

Urate is not filtered at the glomerulus Net reabsorption of urate occurs in the renal tubules in adults

E Uric acid is excreted only by the kidneys Question 16

With respect to renal handling of urate and uric acid

Options for Questions 17-17 A Polycythaemia

B

Allopurinol

C Hypothyroidism

D

Hyperlipidaemia

E Lactic acidosis Question 17

Which one is associated with low plasma uric acid levels?

Options for Questions 18-18 A 1 molecule of ATP is produced per molecule of urea B

2 molecules of ATP are consumed per molecule of urea

C

3 molecules of ATP are produced per molecule of urea

D

2 molecules of ATP are produced per molecule of urea

E

3 molecules of ATP are consumed per molecule of urea

B

Urea is secreted into the proximal tubule

D

Urea is actively absorbed by the distal loop of Henle

Question 18

During the urea cycle

Options for Questions 19-19 A Urea is freely filtered at the glomerulus C

Urea is transferred across the proximal tubule by facilitated diffusion

E 99% of filtered urea is actively reabsorbed Question 19

With respect to renal handling of urea

Options for Questions 20-20 A The glomerulus

B

The proximal convoluted tubule

C The descending limb of the loop of Henle

D

The medullary collecting ducts

E The renal pelvis Question 20

With respect to renal excretion of urea, carrier-mediated reabsorption occurs in

50 random questions for Best of 5 Test Options for Questions 1-1 A Ribose – hexose sugar

B

Deoxyribose – pentose sugar

C Uracil – purine base

D

Ribose – pyrimidine base

E Thymine – purine base

Question 1

With respect to the structure of nucleic acids, which grouping is correct?

Options for Questions 2-2 A Cannot be detected by Northern blotting

B

Can be detected by Western blotting

C Can be detected by Southern blotting and PCR

D

Cannot be detected by PCR

A Has a 3-methylated cap

B

Has a 5-poly-A tail

C Has a start codon AUG

D

Has a sequence that is written in the 3- to 5- direction

A Exons are added in the cytoplasm

B

Introns are removed before transport to the cytoplasm

C Splicing is undertaken by RNA polymerase

D

Thymine replaces Uracil

E Can be detected by Northern blotting and PCR

Question 2 Messenger RNA

Options for Questions 3-3

E Contains the base Thymine

Question 3 Messenger RNA

Options for Questions 4-4

E Ribose is replaced by deoxyribose

Question 4 With respect to the synthesis of messenger RNA

Options for Questions 5-5 A Makes up about 80% of total cellular RNA

B

Is more stable than ribosomal RNA

C Has a secondary structure with hairpin loops

D

Makes up about 99% of total cellular RNA

E Is broken down rapidly after transcription

Question 5 Messenger RNA

Options for Questions 6-6 A

Ribosomal RNA makes up about 80% of total cellular RNA

B

Messenger RNA makes up about 80% of total cellular RNA

C

Transfer RNA makes up about 80% of total cellular D RNA

Ribosomal RNA makes up about 15% of total cellular RNA

E

Transfer RNA makes up about 90% of total cellular RNA

Question 6 With respect to total cellular RNA

Options for Questions 7-7 A

A 40S sub-unit made up of 18S rRNA and 34 different proteins

B

A 20S sub-unit made up of 18S rRNA and 10 different proteins

C

A 60S sub-unit made up of 18S rRNA and 34 different proteins

D

A 100S sub-unit made up of 80S rRNA and 34 different proteins

E

A 10S sub-unit made up of 8S rRNA and 34 different proteins

Question 7 In eukaryotic cells, ribosomes have

Options for Questions 8-8 A 5S, 10S and 20S rRNA molecules

B

5S, 5.8S and 20S rRNA molecules

C 5.8S, 10S and 28S rRNA molecules

D

2.8S, 5S and 28S rRNA molecules

E 5S, 5.8S and 28S rRNA molecules

Question 8

In eukaryotic cells, the ribosomes have 2 sub-units. The larger subunit has

Options for Questions 9-9 A That begins with 5-GU

B

That ends in 5-GU

C That begins with 3-AG

D

That begins with 5-AG

B

Joined together by DNA ligase

D

Produced by the action of DNA synthetase

A Is called transcription

B

Is called translation

C Requires the presence of primers

D

Requires the presence of ribonucleotides

A Recognize specific amino acid sequences

B

Recognize specific proteins

C Recognize specific nucleotides

D

Recognize specific polysaccharides

A Northern blotting – DNA

B

Southern blotting – DNA

C Western blotting – RNA

D

Eastern blotting – mRNA

E That ends with 3-GU Question 9 Introns have a sequence

Options for Questions 10-10 A

Segments of DNA after the double helix has been unwound by DNA helicase

C Separated by DNA ligase E Produced from the leading strand of DNA Question 10

Okazaki fragments are

Options for Questions 11-11

E Is catalyzed by DNA polymerase Question 11

The synthesis of DNA from RNA

Options for Questions 12-12

E Recognize specific DNA sequences Question 12

Restriction endonucleases

Options for Questions 13-13

E Western blotting – DNA Question 13

With respect to techniques used to detect macromolecules

Options for Questions 14-14

A Fragments of DNA outside cells

B

Fragments of RNA outside cells

C DNA species that can replicate outside cells

D

DNA species that can enter cells and replicate within them

A Are viruses

B

Occur naturally in bacteria

C Integrate into bacterial DNA before replication

D

Are bacteria

A Taurine

B

Glutamine

C Lysine

D

Glycine

E

DNA species that can enter cells and inhibit DNA replication

Question 14

Vectors are

Options for Questions 15-15

E Infect viruses Question 15

Plasmids

Options for Questions 16-16

E Alanine Question 16

Which one is an essential amino acid?

Options for Questions 17-17 A Vitamin K

B

Folic acid

C Vitamin B12

D

Vitamin B6

E Vitamin C Question 17

Transamination of amino acids requires the presence of a prosthetic group derived from

Options for Questions 18-18 A

Each collagen molecule has an alpha and a beta chain

B

The collagen peptide has a right handed helical structure

C

The collagen peptide is rich in cysteine and methionine

D

The collagen peptide is rich in proline and hydroxyproline

E The collagen peptide does not contain lysine Question 18

With respect to the structure of collagen

Options for Questions 19-19 A Vitamin D

B

Vitamin E

C Folate

D

Tetrahydrofolate

E Vitamin C Question 19

During collagen synthesis, proline and lysine residues are hydroxylated. This reaction is dependent on which co-factor?

Options for Questions 20-20 A Type 1 collagen has a double helix structure

B

C

All types of collagen have a right handed triple helix D structure

E

Type II and IV collagen have a right handed double helix structure

Question 20

Type II collagen has a left-handed triple helix structure Type IV collagen does not have a helical structure

With respect to the structure of collagen

Options for Questions 21-21 A Contains three different alpha chains

B

Contains two beta chains

C Is found in bone, cartilage and skin

D

Contains two identical and one different alpha chain

A Type I

B

Type II

C Type III

D

Type IV

E Is not found in the skin Question 21

Type I collagen

Options for Questions 22-22

E Type V Question 22

The type of collagen with three identical alpha chains and is present in cartilage

Options for Questions 23-23 A One gene can code for more than one protein

B

One protein can be coded for by more than one gene

C One codon can recognise more than one amino acid D

One amino acid can be recognised by more than one codon

E One codon can have different number of bases

Question 23

The genetic code is degenerate. This means that

Options for Questions 24-24 A

Is produced from the breakdown of proteins in the liver

B

Is produced from the breakdown of purines in the spleen

C

Is produced from the breakdown of pyrimidines in the liver

D

Is produced from the breakdown of purines in the liver

E

Is produced from the breakdown of nucleotides in reticulo-endothelial cells

B

Aldose and ketose forms

Question 24

Uric acid

Options for Questions 25-25 A Hexose and pentose forms C

The asymmetry of the C atom nearest to the aldehyde D or ketone group

The asymmetry of the C atom furthest away from the aldehyde or ketone group

E The asymmetry of the aldehyde or ketone group Question 25

D and L forms of monosaccharides refer to

Options for Questions 26-26 A Glucose

B

Lactose

C Maltose

D

Galactose

E Sucrose Question 26

Which one is a non-reducing sugar?

Options for Questions 27-27 A Is not found in cell membranes

B

Is a precursor of vitamin D

C Is a precursor of vitamins A and E

D

Cannot be synthesised by humans and must be obtained from the diet

A Are the smallest types of lipoprotein

B

Are the most dense lipoprotein

C Have a mass of about 400kDa

D

Have a protein content of 15-20%

E Is a C20 compound Question 27

Cholesterol

Options for Questions 28-28

E Have a density of about 0.095 g/ml Question 28

Chylomicrons

Options for Questions 29-29 A

LDL is taken up by cells through receptor-mediated B endocytosis

C The LDL receptor is located in the cytoplasm

D

The major lipid in LDL is triglyceride High intra-cellular cholesterol levels results in increased expression of the LDL receptor

E The protein content of LDL is 2-5% Question 29

With respect to the metabolism of low density lipoprotein (LDL)

Options for Questions 30-30 A

Skeletal muscle glycogen is used to maintain blood B glucose levels

C Liver glycogen is stored in the lysosomes E

D

Liver, but not skeletal muscle glycogen is used to maintain blood glucose levels Liver glycogen is stored in the endoplasmic reticulum

Glycogen is stored in granules within the cell membrane

Question 30

With respect to glycogen metabolism

Options for Questions 31-31 A Phosphorylase

B

Glucosidase

C Phosphoglucomutase

D

Glucose-6-phosphatase

E Glucose-1-phosphatase Question 31

During glycogenolysis, which enzyme converts glucose-1-phosphate to glucose-6-phosphate?

Options for Questions 32-32 A Glucagon inhibits glycogenolysis

B

Glucagon stimulates glycogen synthesis

C Calcium ions inhibit glycogenolysis

D

Calcium ions stimulate glycogen synthesis

E

Glucagon stimulates the phosphorylation of phosphorylase b

Question 32

With respect to the regulation of glycogen metabolism

Options for Questions 33-33

A Adrenalin inhibits glycogenolysis C

Adrenalin stimulates the phosphorylation of phosphorylase b

E

Adrenaline stimulates the phosphorylation of protein phosphatase I

Question 33

B

Adrenalin stimulates glycogen synthesis

D

Adrenalin activates protein phosphatase I

With respect to the regulation of glycogen metabolism

Options for Questions 34-34 A One

B

Two

C Three

D

Four

E Two or three depending on oxygen levels Question 34

How many molecules of ATP are generated per glucose molecule during glycolysis?

Options for Questions 35-35 A The production of 2 molecules of ATP

B

The production of 2 molecules of GTP

D

The production of 2 molecules of ATP and 2 molecules of GTP

A The lysosomes

B

The cytoplasm

C The golgi apparatus

D

The smooth endoplasmic reticulum

A Glucagon

B

Adrenaline

C ACTH

D

Noradrenaline

C

The hydrolysis of 2 molecules of ATP and 2 molecules of GTP

E

The hydrolysis of 4 molecules of ATP and 2 molecules of GTP

Question 35

Gluconeogenesis results in

Options for Questions 36-36

E The rough endoplasmic reticulum Question 36

Fatty acid synthesis occurs in

Options for Questions 37-37

E Insulin Question 37

Which one inhibits the activity of hormone-sensitive lipase?

Options for Questions 38-38 A Is catalysed by fatty acid synthase

B

Results in the generation of ATP

C Results in the hydrolysis of ATP to ADP

D

Results in the hydrolysis of ATP to AMP

E Occurs in the mitochondria Question 38

Fatty acid oxidation begins with the conversion of fatty acids to fatty Acyl CoA. This reaction

Options for Questions 39-39 A Are produced mainly by skeletal muscle

B

Are metabolised mainly by the brain

C Can be used as fuel by the heart and renal cortex

D

Are the main fuel used by the brain during exercise

A Phosphorylase and glycogen synthase

B

Glycogen synthase and hormone-sensitive lipase

C Phosphorylase and hormone-sensitive lipase

D

Phosphorylase only

E

Are the main fuel used by the renal medulla and the adrenal gland

Question 39

Ketone bodies

Options for Questions 40-40

E Hormone-sensitive lipase only Question 40

The following enzymes are activated in the post-absorptive phase of starvation

Options for Questions 41-41 A 6 ATP and 6 GTP

B

12 ATP and 12 GTP

C 12 ATP and 1 GTP

D

3 ATP and 1 GTP

E 4 ATP and 2 GTP Question 41

Each turn of the citric (tri-carboxylic) acid cycle produces

Options for Questions 42-42 A A molecule that increases the rate of the reaction

B

C A molecule that modifies the activity of the enzyme D E

A molecule that reduces the rate at which equilibrium is reached

A molecule that increases the rate at which equilibrium is reached A molecule that alters the product of the reaction

Question 42

With respect to the properties of enzymes, a cofactor is

Options for Questions 43-43 A Equal to the Michaelis constant

B

Proportional to the substrate concentration

C Proportional to the product concentration

D

Proportional to the enzyme concentration

E Equal to the square root of the Michaelis constant Question 43

With respect to enzyme kinetics, when there is an excess amount of substrate, the initial velocity of the reaction is

Options for Questions 44-44 A

The enzyme concentration at which the initial velocity is half of Vmax

B

The initial velocity at t = 0.5

C

The substrate concentration at which the initial velocity is half of Vmax

D

The enzyme concentration at which the initial velocity is proportional to the substrate concentration

E

The substrate concentration at which the initial velocity is equal to Vmax

Question 44

With respect to enzyme kinetics, the Michaelis constant is

Options for Questions 45-45 A Svedberg units

B

MicroM per second

C Katal

D

Michaelis units

A A rectangular hyperbola

B

The Michaelis-Menten plot

C The Lineweaver-Burk plot

D

Intercepts the x-axis at Vmax

E Kilo Joules Question 45

The SI unit for enzyme activity is

Options for Questions 46-46

E Has a slopw = Km Question 46

With respect to enzyme kinetics, a graph plotting 1/V0 against 1/[S] is

Options for Questions 47-47 A Reversible inhibition is always competitive C

Irreversible inhibitors bind to enzymes by noncovalent forces

B

Non-competitive inhibition is always irreversible

D

Reversible inhibitors bind to enzymes by covalent forces

E

Reversible inhibitors can be competitive or noncompetitive

Question 47

With respect to the different types of enzyme inhibitors

Options for Questions 48-48 A Sucrase converts sucrose to glucose and galactose

B

Lactase converts lactose to glucose and fructose

C Maltase converts maltose to glucose and fructose

D

Sucrase converts sucrose to glucose and fructose

E Maltase converts maltose to glucose and galactose Question 48

During the digestion of carbohydrates

Options for Questions 49-49 A Begins in the mouth

B

Does not occur in the stomach

C Is undertaken by amylase and lipase

D

Occurs in the mouth and stomach

A Translation

B

Transcription

C Reverse transcription

D

Polymerisation

E Begins in the stomach Question 49

The digestion of lipids

Options for Questions 50-50

E Hybridisation Question 50

The process by which mRNA is made from DNA is

20 random questions for Best of 5 Test Options for Questions 1-1 A Include glucose and fructose but not galactose

B

Include glucose, fructose and maltose

C Are all reducing sugars

D

All have 6 carbon atoms

E Are always aldose sugars

Question 1 Monosaccharides

Options for Questions 2-2 A Hexose and pentose forms C

B

The asymmetry of the C atom nearest to the aldehyde D or ketone group

Aldose and ketose forms The asymmetry of the C atom furthest away from the aldehyde or ketone group

E The asymmetry of the aldehyde or ketone group

Question 2 D and L forms of monosaccharides refer to

Options for Questions 3-3 A

Three identical fatty acid chains esterified to a glycerol backbone

B

Three fatty acid chains esterified to a galactose backbone

C

Three fatty acid chains esterified to a glycerol backbone

D

Three glycerol molecules esterified to a fatty acid chain

E

Three galactose molecules esterified to a fatty acid chain

A Three identical fatty acid chains

B

Three glycerol molecules

C Unsaturated fatty acid chains

D

Saturated fatty acid chains

Question 3 Triglycerides are composed of

Options for Questions 4-4

E Only one fatty acid chain

Question 4 Simple triglycerides have

Options for Questions 5-5 A Is converted to HDL as triglycerides are hydrolysed B

Does not contain phospholipids

C Is converted to IDL and then LDL

Is synthesised from LDL

D

E Transports cholesterol from the tissues to the liver

Question 5 Very low density lipoprotein (VLDL)

Options for Questions 6-6 A

Is an oligosaccharide containing glucose and galactose

B

C Is a polysaccharide containing glucose and galactose D E

Is a branched chain polysaccharide containing glucose and lactose

Question 6 Glycogen

Is a branched chain polysaccharide containing glucose Is not stored in skeletal muscle

Options for Questions 7-7 A Glucagon inhibits glycogenolysis

B

Glucagon stimulates glycogen synthesis

C Calcium ions inhibit glycogenolysis

D

Calcium ions stimulate glycogen synthesis

E

Glucagon stimulates the phosphorylation of phosphorylase b

Question 7 With respect to the regulation of glycogen metabolism

Options for Questions 8-8 A Other carbohydrates

B

Free fatty acids

C Non-carbohydrate precursors

D

Amino acids

E Lactate

Question 8 Gluconeogenesis is the formation of glucose from

Options for Questions 9-9 A Gluconeogenesis

B

Glycolysis

C Glycogen synthesis

D

Glycogenolysis

E The Cori cycle Question 9 The enzyme fructose 1,6 bisphosphatase plays a key role in

Options for Questions 10-10 A Pyruvate is converted to glucose in skeletal muscle

B

Pyruvate is converted to lactic acid by the liver

C NAD+ is converted to NADH in skeletal muscle

D

Lactate is converted to glucose by the liver

A Glucagon

B

Adrenaline

C ACTH

D

Noradrenaline

E Glucose is converted to lactate by the liver Question 10

During the Cori cycle

Options for Questions 11-11

E Insulin

Question 11

Which one inhibits the activity of hormone-sensitive lipase?

Options for Questions 12-12 A Occurs exclusively in the cytoplasm

B

Occurs exclusively in the mitochondria

D

Begins in the mitochondria and continues in the cytoplasm

A Glycerol

B

Free fatty acids

C Fatty Acyl CoA

D

Acetyl CoA

C

Begins in the cytoplasm and continues in the mitochondria

E Results in the production of glycerol Question 12

Fatty acid oxidation

Options for Questions 13-13

E Triglycerides Question 13

With respect to fatty acid oxidation, which substrate is transferred from the cytosol to the mitochondria for beta oxidation?

Options for Questions 14-14 A The rate of glycolysis exceeds oxygen availability

B

The rate of fatty acid oxidation exceeds oxygen availability

C

The rate of fatty acid oxidation exceeds the rate of glycerol synthesis

D

The rate of carbohydrate breakdown exceeds the rate of protein synthesis

E

The rate of fatty acid oxidation exceeds the rate of carbohydrate breakdown

B

Acetic acid, acetoacetate and beta-hydroxybutyrate

Question 14

Ketone bodies are produced when

Options for Questions 15-15 A Acetone, acetic acid and acetoacetate

C Acetyl CoA, acetoacetate and beta-hydroxybutyrate D

Glycerol, acetoacetate and acetone

E Acetone, acetoacetate and beta-hydroxybutyrate Question 15

Ketone bodies include

Options for Questions 16-16 The activity of fructose-1,6-bisphoaphatase is increased

B

The activity of phosphofructokinase is increased

C Glucose is converted to amino acids by the liver

D

Insulin concentrations increase

A

E The brain begins to use free fattu acids as fuel Question 16

During the gluconeogenic phase of starvation

Options for Questions 17-17 A The nucleus

B

The mitochondria

C The mitochondria and cytoplasm

D

The lysosomes

E The cytoplasm Question 17

The pentose phosphate pathway occurs in

Options for Questions 18-18 A Resulta in the oxidation of glucose to CO2 and water B

Cannot utilise acetyl CoA

C Begins in the cytosol

Occurs in mitochondria

D

E Can occur under anaerobic conditions Question 18

The citric acid (tri-carboxylic acid) cycle

Options for Questions 19-19 A 1

B

2

C 3

D

4

E 5 Question 19

During the citric acid cycle, how many molecules of CO2 are produced per molecule of acetyl CoA?

Options for Questions 20-20 A Fatty acids

B

Glucose

C Amino acids

D

Porphyrin

E Folic acid Question 20

Which one is not a product of intermediate molecules derived from the citric acid cycle?