Flashcards in BioChem Deck (153)
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1
Oxidoreductases
Transfer elecltrons from a donor to an acceptor
2
Transferases
Transfer a functional group
3
Isomerases
Rearrange / isomerase a molecule
4
Lyases (syntheses)
Add or remove atoms to or from a double bond
5
Ligases “synthetases”
Form (C-O C-S C-N C-C) bonds with the hydrolysis of atp
6
Hydrolases
Cleave bonds via the addition of water
7
Enzyme that uses Cu as a cofactor
Cytochrome c oxidase
8
Enzyme that uses Fe as cofactor
Heme proteins (hemoglobin and myoglobin) need Fe to bind O2
9
Enzyme that requires Mg as a cofactor
ATPases
10
Enzyme that requires Se as a cofactor
Glutathione peroxidase- detoxifies hydrogen peroxide
11
Enzyme that requires Zn as a cofactor
Superoxide dismutase - binds the free radical of molecular oxygen
12
2 types of coenzymes
Co substrate - temporary association such as NAD+
Prosthetic - permanent association Heme
13
Ideal temp for enzyme activity
37 degrees C
14
Ideal pH for enzyme activity
4-8 with the exception of pepsin
15
Gastric proton pumps are on what type of cell
Parietal cells
16
What variable stands for enzyme - substrate affinity?
Km
17
/What shape is a Michaelis menten plot?
Hyperbolic
18
/What shape is a lineweaver Burke plot?
Linear
19
Competitive inhibitor
Resemble substrate - compete for the active site on an enzyme
No effect on vmax - increase Km
20
1/2 vmax
Km
21
Lineweaver Burke x intercept
-1/Km
22
Y intercept lineweaver Burke
1/Vmax
23
Slope lineweaver Burke plot
Km/Vmax
24
Non competitive inhibitor
Bind to E or ES complex not at the active site
Decreases Vmax
Unchanged Km
Effect cannot be altered by increasing substrate concentration
25
Uncompetitive inhibition
Decrease in vmax and Km by the same factor - lineweaver Burke plot with and without inhibitor yields parallel lines
26
How can you inhibit metaloenzymes
Use metal cofactor - chelating the cofactor will inhibit enzyme activity
This can be used to stop lead poisoning through using edta which is a lead chelator (lead normally will bind heme rendering it useless)
27
Enzyme inactivation
VMax? Up or down
Km? Up or down
Reversible or not?
Similar lineweaver Burke plot to what type on inhibition?
Vmax decreased
Unchanged Km
Irreversible
Non competitive is similar but is reversible
28
Allosteric enzymes
Type of bond ?
Location of bond?
Positive or negative effect?
Noncovalent bond
Not at the catalytic site
Induce conformational change to create a positive or negative impact
Utilize feedback inhibition where product of enzyme is a negative effector
29
What shape plot does a allosteric enzyme create
Sigmoidal
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