Amino acids and Proteins Flashcards
(25 cards)
What are the essential and nonessential amino acids?
1) LLTTVIPMH
2) 4A,3G,CPST
Lysine, Tryptophan, Asparagine, Aspartate, Glutamate, Glutamine letters?
K, W, N, D, E Q
Selenocysteine is needed for the functioning of what 2 enzymes?
Glutathione peroxidase, Thioredoxin reductase
Proline has a … amine as opposed to the other amino acids that all have a … amine?
secondary, primary
All amino acids are chiral except…
Amino acids by convention are in the … form(L or D)
Glycine
L
Non-polar A.A. include
Glycine, Alanine, Valine, Leucine, Isoleucine, Methionine
(GAVLIM)
Proline is an exception.
VIL= BCAA
Polar neutral A.A. include…
Asparagine, Glutamine, Serine, Threonine, Cysteine.
(AGCST)
Function?
1) Hydroxyproline, Hydroxylysine
2) Y-carboxy glutamate
3) Citrulline, Ornithine
4) B-alanine
5) GABA
6) Gaba pentin
7) Penicillamine
1) In collagen and myosin
2) In prothrombin
3) Urea cycle
4) intermediate of coA
5) Neurotransmitter from glu
6) epilepsy treatment
7) Wilson disease treatment(chelates copper)
If pH > pI, protein will have a net … charge.
If pH < pI, protein will have a net … charge.
-ve, +ve
Pka’s to memorize(0 if pH lower than acid or higher than base)
1) Asp + Glu
2) Cys
3) Tyr
4) His
5) Lys
6) Arg
7) N and C
1) around 4
2) 8
3) 10
4) 6 ~ 7
5) 9.5-10
6) 12
7) 9 and 2
Types of bonds involved in:
1) Secondary
2) Tertiary
3) Quaternary
1) Peptide
2) R group hydrophobic, salt bridges, and mainly disulfide bonds(covalent)
3) Non-covalent and rare disulfide
Most destructive A.A is…
Proline(it has no H-bonds)
Keratin is unique since it
Flips between alpha helix and B-sheet(dry hair vs heated)
6 bonds keep iron in the middle of heme…
1) 4 N from tetrapyrrole rings
2) Fe-His at F8(proximal His)
3) Fe-His at E7(Distal His = makes it hard for O2 to bind initially and prevents Fe2+ > Fe 3+)
3 factors influence O2 unloading
1) decrease in pH(more acid)
2) Increase CO2
3) 2,3-bisphosphoglycerate
Lung > Tissue
1) Deoxy hemo in lungs becomes oxy due to high O2 pressure
2) Oxy hemo releases H+ to make carbonic acid
3) Oxy hemo goes to tissues(carbonic acid breakdown) where pH is low and unloading occurs
4) becomes Deoxy again binds CO2 and exhale
5) Repeat
… is an endopeptidase that cleaves C terminus of aromatic A.A.
Chymotrypsin
1) Marfan syndrome
2) Ehlers-Danlos
1) Defect in fibrillin
2) Improper triple helix of collagen(Vit C deficiency)
Urea and guanidino residues, when added to a protein, destroy…
Secondary and tertiary structures
1) Sodium deoxycholate
2) SDS
1) lipid emulsifier
2) Unfold polypeptide chain
What destroys disulfide bonds?
Detergents and reducing agents
1) HSP 70
2) HSP 60
1) Guide for protein final destination
2) Isolation chamber for proper protein folding.
Both use ATP
1) Prolyl cis-trans isomerase
2) Protein disulfide isomerase
1) trans peptide bond > cis peptide bond
2) reshuffle/modify disulfide bonds(reduced) or create new ones(oxidized)
T/F: B-sheets are more toxic than alpha helices.
True
