Chapter 12-3

DNA, RNA & Protein Bio 30 NWRC

Central Dogma • If you were going to build a house what would you do first? • You would likely need a plan or a blueprint which gives you the design of the house…

Central Dogma • A cell needs similar plans to build proteins

Central Dogma • The plans need to be read by a contractor and the area where the house is to be built needs to be staked out

Central Dogma • The mRNA (messenger) reads the plans of the DNA and sends the message to the building site (ribosome)…

Central Dogma • Materials (Amino Acids) will be brought in according to the plans by delivery trucks (tRNA)…

Central Dogma • The whole process of building the house will cost $$$ (energy) to the architect (the cell)

Central Dogma –Another Analogy Baking a Cake (PROTIEN)

You need also UTENSILS (RNA) And INGREDIENTS (AMINO ACIDS)

In order to make the cake you need a cookbook…DNA is the Cookbook (instructions for making a Protein

Central Dogma

RNA • RNA: Ribonucleic acid. Single-stranded where DNA is double-stranded, messenger RNA carries single pages of instructions out of the nucleus to places they're needed throughout the cell. Transfer RNA helps translate the mRNA message into chains of amino acids in the ribosomes.

RNA types • 1. Ribosomal RNA (rRNA): make up ribosomes • 2. Transfer RNA (tRNA): transport amino acids to ribosomes • 3. Messenger RNA (mRNA): copied from DNA, conveys information from chromosomes to ribosomes

Central Dogma • DNA carries the genetic information of a cell and consists of thousands of genes. Each gene serves as a recipe on how to build a protein molecule. Proteins perform important tasks for the cell functions or serve as building blocks.

Transcription • The DNA is situated in the nucleus, organized into chromosomes. Every cell must contain the genetic information and the DNA is therefore duplicated before a cell divides (replication).

Transcription • When proteins are needed, the corresponding genes are transcribed into RNA (transcription).

Transcription • Notice on the diagram that there is a template and a nontemplate side of the DNA

Transcription • Also notice that a “U” is used instead of “T” for Thymine in RNA

Transcription • The DNA is situated in the nucleus, organized into chromosomes. Every cell must contain the genetic information and the DNA is therefore duplicated before a cell divides (replication). • When proteins are needed, the corresponding genes are transcribed into RNA (transcription).

• To make this possible, a complex machinery, like a copying machine, copies the cells DNA before it divides. That way each daughter cell receives an exact copy of the dividing cell's DNA. This doubling of DNA is called replication.

Assessment • 1. RNA is synthesized from the template strand of DNA and used to assemble AAs into proteins

Assessment • 2. rRNA is the central component of the ribosome, the protein manufacturing machinery of all living cells • mRNA Carries the complimentary code from template to ribosome • tRNA- transports AA to ribosome for protein synthesis

Assessment • 3. A codon is a 3 nucleotide code units on DNA or mRNA • An anticodon is the code unit on tRNA that compliments the mRNA codon

Assessment • 4. RNA polymerase initiates mRNA synthesis during transcription.

For Further study… • Animations and concepts look at the structure of the 4 nucleotides