Amino Acid Structures/Pka Flashcards
Glycine
R = Hydrogen
Disrupts secondary protein structure by creating kinks in alpha-helix b/c so flexible
Symbol: Gly, G
Alanine
R = Methyl (CH3)
canonical example of simple, small, nonpolar AA
Symbol: Ala, A
Valine
R = (C3 in a V)
substitution for glutamic acid causes sickle cell anemia
Symbols: Val, V
Isoleucine
R = C3 w/ a methyl on the 1’
our bodies can’t synthesize, we have to eat
Symbols: Ile, I
Leucine
R = C3, w/ a methyl on the 2’ - just valine with one more carbon before the V
our bodies can’t synthesize, we have to eat
Symbols: Leu, L
Methionine
R = C2, S, methyl has a thioether bond (S-C) not really considered nonpolar involved in angiogenesis and DNA methylation symbols: Met, M
Proline
R = secondary alpha-amino group - the alkyl group forms a bond with the amino group of the protein backbone - 3 C then, connect with N
Disrupts secondary protein structure by creating kinks in alpha-helix
Symbols: Pro, P
Phenylalanine
R = methyl group + benzene ring
if you have phenylketonuria, you can’t convert this to tyrosine
symbols: Phe, F
Cysteine
R = C and a Thiol group Can form disulfide bridges in oxidizing environments (extracellular env) (deprononated and then the neg charged Sulfurs form a covalent bond) Reduced form = Cysteine Oxidized from - Cystine Symbols: Cys, C
Histidine
R = C2 + imidazole side chain
good protein stabilizer b/c it can exists in both protonated and deprotonated forms at physiological pH (the N can be N or NH+)
Symbols: His, H
How do pH and pKa determine protonation?
pH>pKa = deprotonated form
pH
Tyrosine
R = methyl + benzene + hydroxyl at 4’ (a phenol)
more water soluble than F, but still nonpolar
precursor for dopamine, epinephrine and norepinephrine
Symbols = Tyr, Y
Tryptophan
R = methyl + indole (cyclic 4 carbon + amine group with 2 carbons shared with a benzene ring) Symbols = Trp, W
Serine
R = single-carbon alcohol (ch2oh) polar often target for phosphorylation and post-translation modification + signaling we can make it from glycine Symbols = Ser, S
Threonine
R = two carbon alcohol (C2, with a secondary hydroxyl group)
can’t make from glycine
Symbols = Thr, T
Asparagine
R = C + amide (one of 2 AAs that is an amide) Symbols = Asn, N
Glutamine
R = C2 + amide
most common free AA in human blood
Symbols = Gln, Q
Arginine
R = C3 + guanidium group (NHC(NH2+)NH2)
guanidium group positively charged
stabilized by resonance, so it’s the most basic of all AAs
Symbols = Arg, R
Lysine
R = C4 and a primary amine
positively charged and reactive - target of methylation and acetylation
Symbol = Lys, K
Aspartic Acid (Aspartate)
R = C and a carboxyl group
exists in the oxidized form (deprotonated) at biological pH (so neg charged)
Symbols = Asp, D
Glutamic acid
glutamate
R = C2 + carboxyl group Symbols = Glu, E
What amino acids are keteogenic?
ketogenic = can be directly converted into Acetyl-CoA or Acetoacetyl-CoA
they are Leucine (L) and Lysine (K)
What amino acids are glucogenic?
Glucogenic = are metabolized to yield pyruvate or krebs cycle intermediates Alanine (A) Arginine (R) Asparagine (N) Aspartate (D) Cysteine (C) Glutamic Acid (E) Glycine (G) Histidine (H) Valine (V) Methionine (M) Proline (P) Serine (S)
