Page 49 - Cell biology PDG 2024

Amino acids and proteins

Proteins are polymers built from monomeric units called amino acids
Amino acids are α-amino acids:

alpha carbon

H2N – C – COOH
|
R

When R is not H, the alpha carbon is asymmetric, giving rise to isomers
There are 20 amino acids that are classified according to their different
functional groups:
(R-OH) Alcohols
(Ph-OH) Phenol
(R-COOH) Carboxylic acids
(R-SH) Thiols
(R-NH2) Amines

 Protein function depends on:
• The amino acid content
• The amino acid sequence.

 Proteins can fold into many shapes (spherical, ellipsoidal,
long strands)

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