Which of the following amino acids have aliphatic sidechains?
glycine (gly), alanine (ala), valine (val), leucine (leu), proline (pro), and isoleucine (ile)
Which of the amino acids have aromatic sidechains?
phenylalanine (phe), tyrosine (tyr), tryptophan (trp)
Which of the amino acids are basic?
histidine (his), lysine (lys) and arginine (arg)
Which of the amino acids are acidic?
aspartic (asp), glutamic (glu), asparagine (asn), glutamine (gln)
Defects in the metabolism of which amino acid leads to the maple syrup urine disease?
Luecine, isoleucine and valine
"Branched" amino acids
What disorder arise from defects in the metabolism of tyrosine? Phenylalanine?
- Defects in the tyrosine metabolism causes tyrosinosis, albinism and alcaptonuria.
- Defects in phenylalanine cause polyketanuria (PKU)
With respect ot the amino acids that we discussed, what is the cause of pellagra?
A defect in the ability for the body to metabolize tryptophan into niacin
Which amino acids have hydroxyl groups on the sidechain? Which amino acids contain sulfur? When they are in proteins, what kind of rxns do these amino acids occasionally undergo?
- serine (ser) and threonine (thr) have OH sidechains.
- Cysteine (cys) and methionine (met) have sulfur.
- Reactions of -OH groups are phosphorylated.
- Reactions of sulfhyroxyl groups oxidize to form dulsulfide linkages.
Which amino acids are referred to as essential?
histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan and valine.
"Pvt. Tim Hall"
Name at least 4 types of compounds for which amino acids are the precursors
- Hormone synthesis
- Porphyrins, purines, pyrimidines
- Building blocks for proteins (particularly enzymes)