Lecture 11 - Enzymes I Flashcards Preview

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Flashcards in Lecture 11 - Enzymes I Deck (31):
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

transfers a group intra-molecularly

isomerase (forms isomer)

31

covalently links two molecules

ligase (ligate-to join together)