Amino Acids-the Building Blocks Of Proteins

Amino Acids - The Building Blocks of Protein Dr Imran Siddiqui

What are Proteins? Functions of Proteins Proteins are chain of amino acids  Proteins are the most abundant and functionally diverse molecules in living systems.  Virtually every life process depends on proteins. 

Enzymes and hormones Contractile proteins Bone Blood proteins

Amino Acids  





Structure of the amino acids More than 300 different amino acids have been described in nature, Only twenty are commonly found as constituents of mammalian proteins. Each amino acid has a carboxyl group, an amino group, and a distinctive side chain ("R-group") bonded to the α -carbon atom.

The Basic Block: Amino Acid Sidechain R H + N

Cα

OC

H H

H Amino group

“zwitterion”

O Carboxyl group

The 20 amino acids 3-letter

Amino acid

3-letter

Amino Acid

Ala

Alanine

Met

Methionin

Cys

Cysteine

Asn

Asparagine

Asp

Aspartic Acid

Pro

Proline

Glu

Glutamic Acid

Gln

Glutamine

Phe

Phenylalanine

Arg

Arginine

Gly

Glycine

Ser

Serine

His

Histidine

Thr

Threonin

Ile

Isoleucine

Val

Valine

Lys

Lysine

Trp

Tryptophan

Leu

Leucine

Tyr

Tyrosine

D & L Forms of Amino Acids

A. Amino acids with nonpolar side chains

B. Amino acids with uncharged polar side chains

C. Amino acids with acidic side chains D. Amino acids with basic side chains

Peptide Bond

Animation

Summary 

All proteins are polymers built up from 20 amino acids.



Each amino acid shares a common main chain; the remaining atoms form sidechains, that can be hydrophobic, polar or charged. Nomenclature of Amino Acids Formation of Peptide Bonds

 