Study Set Content:
amino acids
peptide
protein
The Building Blocks for Proteins
Amino acids
Amino acid: an organic compound that contains both an
amino(-NH₂) group and a carboxyl (-COOH) group
•the amino acids found in protein are always
α-amino acids.
the amino group and the carboxyl group are attached to the α-carbon atom
Alpha amino acid:
R group - polarity
nonpolar, polar but neutral, acidic, and basic)
r-group or side chain
amino group
carboxyl group
alpha-hydrogen
Imino acid
• In a typical α-amino acid, four different groups are attached to the
α-carbon (–COOH, –NH2 , –R, and –H).
stereoisomers which are nonsuperimposable mirror images of each other.
• Enantiomer
There are two different forms of the chiral amino acids:
the D- and the L-isomers
Nonpolar amino acids
Glycine
alanine
Valine
leucine
Isoleucine
Proline
Phenylalanine
Methionine
Tryptophan
Polar neutral amino acids
Serine
Cysteine
Threonine
Asparagine
Glutamine
Tyrosine
Polar acidic amino acids
aspartic acid, glutamic acid
Polar Basic Amino Acids
Histidine, lysine, arginine
