DLA 15 Flashcards
general structure of an amino acid?
carboxylic group
R group
H
amino group
All AA’s are chiral except
glycine
Naturally occurring amino acids are in what what configuration?
L
Why is proline different?
It has a ring structure
lead to kinks in protein chains
Where is proline found a lot in?
collagen
What AA’s are nonpolar and aliphatic ?
glycine, alanine and proline
What AA’s are nonpolar, aliphatic, and have branched side chains?
Valine, leucine, and isoleucine
What AA’s have aromatic side chains?
phenylalanine, tyrosine and tryptophan
What amino acids contain sulfur?
methionine and cysteine
What AA can make disulfide bonds?
cysteine by oxidation and reduction breaks the bond
What amino acids are polar and non-charged?
asparagine and glutamine
Serine and Threonine
What AA’s can be phosphorylated and glycosylated?
Serine & threonine
What AA’s have negative (acidic) side chains at physiological pH?
Aspartate and glutamate
What AA’s have positive (basic) side chains?
Arginine and lysine
SOMETIMES histidine
What AA is favorable in buffering the normal pH of cells?
Histidine
How is GABA formed?
decarboxylation of the a-carboxyl group of glutamate
How is histamine formed?
decarboxylation of histidine
How is serotonin made?
It is a derivative of tryptophan
dopamine, norepinephrine and epinephrine are formed from what AA?
tyrosine
How is dopamine made?
tyrosine is hydroxylated to dihydroxy-phenylalanine (L-DOPA)
L-DOPA is decarboxylated to dopamine, the first catecholamine.
How are AA linked together?
peptide bonds
a carboxyl group of one amino acid and the a amino group of the following amino acid
