Flashcards in Lecture 11 - Enzymes I Deck (31)
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1
The most common of all enzymatic reactions.
Redox (oxidation-reduction) reactions.
2
Primary f(x)s of enzymes
Lower activation energy (Ea) and stabilize the transition state)
3
How does one increase the production of products (according to Le Chatlier's Principle)?
Decrease [product] or increase [reactants]
4
What is meant by "coupled reactions" in terms of biochemical reactions?
The energies of a set of reactions are additive. In other words, if A-> B has a (+) G, and B->D has a (-) G, they can be added together. If the sum of both G's is (-), the reaction is OVERALL spontaneous.
5
G*'
-RTln([prod]/[react])
6
These reactions revolve around the transfer of electrons.
Oxidation-reduction reactions
7
Gain of an e-
Reduction
8
loss of e-
Oxidation
9
Gain of H+
Conjugate acid
10
Loss of H+
Acid
11
What portion of an enzyme determines specificity for a substrate?
Active site
12
Cleavage of peptide bonds
Protelytic reactions
13
What is the Vmax?
The maximum rate (reaction velocity) at which a reaction can occur.
14
What produces a maximum velocity (Vmax) in reactions?
The complete saturation of the active site on an enzyme.
15
3-D region or crevice that is produced after the residues from various parts of a protein come together in the 3* structure
active site
16
Highly unstable intermediate in enzymatic reactions
transition state
17
What is the "purpose" of an enzyme (specifically, HOW does an enzyme catalyze reactions)?
by lowering the activation energy of a given reaction
18
Why are many vitamin deficiencies the cause of enzymatically driven health problems?
Often, vitamins serve as co-factors for enzymes. W/o the co-factor, the enzyme is an "apoenzyme," devoid of function.
19
An enzyme that contains its co-factor and is biologically active
holoenzyme ("holo-" = "complete")
20
Two f(x)s of metals as co-factors
Stabilize A.S. and donate e- to the chemical reaction
21
small organic molecules used as a co-factor
co-enzymes
22
An enzyme w/o its necessary co-factor
apoenzyme
23
Tightly bound co-enzymes are known also as _____.
prosthetic groups
24
Pathophysiology of scurvy
A lack of co-factor (Vit. C) for prolyl hydroxylase, prevents addition of -OH in collage
25
Pathophysiology of ariboflavinosis
A lack of riboflavin (Vit. B2) prevents activation of FAD; this causes decreased glutathione reductase function, and results in UV light damage to areas exposed to the sun through production of free radicals (no FAD to "snag" high energy free radicals)
26
enzyme that transfers e- between compounds
oxidorecutase
27
enzyme that moves f(x) group between compounds
transferase
28
catalyze hydrolysis of covalent bonds
hydrolases
29
Form double bonds by the addition of removal of groups
lyase
30
