AMINO ACID
• Amino acid: a compound that contains an amino
group, a carboxyl group and a side-chain that is
specific to each amino acid.
• Amino acid: an amino acid in which the amino group
is on the carbon adjacent to the carboxyl group.
• The are 20 common α-amino acids used by the
ribosomes to make proteins. These 20 have L
chirality at the α- carbon.
• The building blocks of proteins
• • 20 amino acids are naturally incorporated into polypeptides
and are called proteinogenic or standard amino acids. These
20 are encoded by universal genetic code.
• • 10 standard amino acids (Lys, Met, His, Leu, Ile, Thr, , Try,
Phe, Val & Arg) are called “essential” for humans because they
cannot be created from other compounds by the human
body, and so must be taken in as food.
• • From these building blocks different organisms can make
such widely diverse products as enzymes, hormones,
antibodies, antibiotics, and a myriad of other substances
having distinct biological activities.
• • Also used as single molecules in biochemical pathways
• | H2N—C —COOH | H 3
• Chemistry of Amino Acids
• Two functional groups:
carboxylic acid group–amino group on the alpha (α) carbon
• Have different side groups (R)–Properties dictate behavior of AAs
Stereochemistry of AAs
