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Flashcards in Enzymes Deck (18):
1

Properties of Enzymes

- Lowering activation energy
- Don't alter concentration of reactant/products
- Don't alter delta G
- Stabilize the transistion state intermediate
- Provide more energetically favorable reaction

2

What are Cofactors

Metal ions, interact with enzyme via noncovalent interaction, and they stabilize the active site

3

What are coenzymes

vitamins

4

Protein that requires Cu

Cytochorme C oxidase: accepts electrons from cytochrome -c in the electron transport chain

5

Protein that requires Fe

Heme proteins (hemoglobin and myoglobin): Require Fe2+ to bind O2

6

Protein that requires Mg

ATPases: Hydrolyze ATP to ADP and use the released energy to do mechanical work

7

Protein that requires Se

Glutathione Peroxidase: detoxifies hydrogen peroxide

8

Protein that requires Zn

Superoxide dismutase: bind the free radical of molecularoxygen

9

Factors that affect Enzyme action

Temperature: 37
pH: 4-8
Covalent Modification: phosphorylation or dephosphorylation

10

Gastric PPI

H+/K+ ATPase, parietal cells, H + Cl forms HCl but PPI reduce HCl

11

Allosteric Enzyme

noncovalent binding of a metabolite to a site other than the catalytic site.There are positive (activators) and negative (inhibitors)

12

Irreversible Inhibitor

Example: Pb, decrease Vmax but does not change Km

13

Competitive Inhibitor

Increase Km (decrease affinity) and Vmax does not change

14

Noncompetitive inhibitor

Binds to free and substrate-bound enzyme. Decrease Vmax but no change to Km.

15

Uncompetivite

Binds only to enzyme-substrate complex. Decrease in Km and Vmax by same factor

16

Isozyme

Same Catalytic function, different primary sequence

17

Main marker for Myocardial Infarction

Troponin

18

Proenzyme/ Zymogen

Precursor to enzyme, usually needs proteolytic breakdown.