Biochemistry 1 Flashcards
Glycine
Gly, G
non-polar
Alanine
Ala, A
non-polar
Valine
Val, V
non-polar
Leucine
Leu, L
non-polar
Isoleucine
Ile, I
non-polar
Methionine
Met, M
non-polar
Phenylalanine
Phe, F
non-polar
Tryptophan
Trp, W
non-polar
Proline
Pro, P
non-polar
Arginine
Arg, R
positive
Histidine
His, H
positive
Lysine
Lys, K
positive
Aspartic Acid
Asp, D
negative
(aspartate)
Glutamic Acid
Glu, E
negative
(glutamate)
Serine
Ser, S
polar
Threonine
Thr, T
polar
Asparagine
Asn, N
polar
Glutamine
Gln, Q
polar
Cysteine
Cys, C
polar
pKa = 10.28
Tyrosine
Tyr, T
non-polar
isoelectric point
pI neutral = average of pKa amine and pKa carboxyl
pI acidic = average of pKa R group and pKa carboxyl
pI basic = average of pKa R group and pKa amine
amino acid pKa
carboxyl group = 2
acidic R group = 4
histidine group = 6
amine group = 9
basic R group = 11-12
trypsin
arginine, lysine
chymotrypsin
phenylalanine, tryptophan, tyrosine
Strecker Synthesis
nucleophilic addition → nucleophilic acyl substitution
Gabriel Synthesis
transferase
transfer functional groups → kinase
hydrolase
hydrolysis
isomerase
rearranges bonds within a molecule to form an isomer (epimerase)
lyase
AB ⟷ A + B
cleavage / synthesis
ligase
addition / synthesis of large molecules
usually ATP dependent
Km
measure of an enzyme’s affinity for its substrate
↑ Km = ↓ affinity
↓ Km = ↑ affinity
Km = [S] @ 1/2 Vmax
Michaelis-Menten Equation
Lineweaver-Burk Plot
y-intercept = 1/Vmax
x-intercept = 1/Km
competitive inhibitor
inhibitor binds to active site
Vmax → no change
Km → increases
uncompetitive inhibitor
inhibitor binds to E-S complex
Vmax → decreases
Km → decreases
non-competitive inhibitor
inhibitor binds away from active site → shape of enzyme changes
has equal affinity for enzyme and E-S complex
Vmax → decreases
Km → no change
mixed inhibitor
inhibitor has unequal affinity for enzyme and E-S → favors one over the other
Vmax → decreases
↑ affinity for enzyme → Km = increases
↑ affinity for E-S → Km = decreases
