Lecture 11 - Enzymes I Flashcards Preview

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Flashcards in Lecture 11 - Enzymes I Deck (31)
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1
Q

The most common of all enzymatic reactions.

A

Redox (oxidation-reduction) reactions.

2
Q

Primary f(x)s of enzymes

A

Lower activation energy (Ea) and stabilize the transition state)

3
Q

How does one increase the production of products (according to Le Chatlier’s Principle)?

A

Decrease [product] or increase [reactants]

4
Q

What is meant by “coupled reactions” in terms of biochemical reactions?

A

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
Q

G*’

A

-RTln([prod]/[react])

6
Q

These reactions revolve around the transfer of electrons.

A

Oxidation-reduction reactions

7
Q

Gain of an e-

A

Reduction

8
Q

loss of e-

A

Oxidation

9
Q

Gain of H+

A

Conjugate acid

10
Q

Loss of H+

A

Acid

11
Q

What portion of an enzyme determines specificity for a substrate?

A

Active site

12
Q

Cleavage of peptide bonds

A

Protelytic reactions

13
Q

What is the Vmax?

A

The maximum rate (reaction velocity) at which a reaction can occur.

14
Q

What produces a maximum velocity (Vmax) in reactions?

A

The complete saturation of the active site on an enzyme.

15
Q

3-D region or crevice that is produced after the residues from various parts of a protein come together in the 3* structure

A

active site

16
Q

Highly unstable intermediate in enzymatic reactions

A

transition state

17
Q

What is the “purpose” of an enzyme (specifically, HOW does an enzyme catalyze reactions)?

A

by lowering the activation energy of a given reaction

18
Q

Why are many vitamin deficiencies the cause of enzymatically driven health problems?

A

Often, vitamins serve as co-factors for enzymes. W/o the co-factor, the enzyme is an “apoenzyme,” devoid of function.

19
Q

An enzyme that contains its co-factor and is biologically active

A

holoenzyme (“holo-“ = “complete”)

20
Q

Two f(x)s of metals as co-factors

A

Stabilize A.S. and donate e- to the chemical reaction

21
Q

small organic molecules used as a co-factor

A

co-enzymes

22
Q

An enzyme w/o its necessary co-factor

A

apoenzyme

23
Q

Tightly bound co-enzymes are known also as _____.

A

prosthetic groups

24
Q

Pathophysiology of scurvy

A

A lack of co-factor (Vit. C) for prolyl hydroxylase, prevents addition of -OH in collage

25
Q

Pathophysiology of ariboflavinosis

A

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
Q

enzyme that transfers e- between compounds

A

oxidorecutase

27
Q

enzyme that moves f(x) group between compounds

A

transferase

28
Q

catalyze hydrolysis of covalent bonds

A

hydrolases

29
Q

Form double bonds by the addition of removal of groups

A

lyase

30
Q

transfers a group intra-molecularly

A

isomerase (forms isomer)

31
Q

covalently links two molecules

A

ligase (ligate-to join together)