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Molecules to Medicine Unit 1 > Enzyme Kinetics > Flashcards

Flashcards in Enzyme Kinetics Deck (21):
1

What is a catalyst?

A catalyst is a molecule that increases the rate in a chemical reaction without themselves being changed in the process.

2

Enzymes lower the ___________ of a reaction.

Activation energy

3

The _________ of an enzyme is where catalysis takes place.

Active Site

4

Bound metal ions can help __________ or can be a powerful driving force in ____________

position the substrate; oxidation-reduction reactions

5

In general acid-base chemistry, the amino acid side chain of an enzyme can donate or accept _________ to stabilize transitions states.

Protons

6

When cofactors or coenzymes are tightly bound to an enzyme, it is called a ____________

Prosthetic group

7

The velocity of a given enzymatic reaction depends on __________

The amount of substrate

8

Km is the amount of substrate needed for the enzyme velocity to be at __________

1/2Vmax

9

Kcat is the number of substrate molecules converted to product in a given unit time for a given enzyme molecule when ____________

The enzyme is saturated with substrate

10

The __________ the number from the ratio of Kcat/Km, the closer to enzymatic perfection

Larger

11

What are the three types of reversible inhibitors?

1. Competitive 2. Uncompetitive 3. Mixed

12

A competitive inhibitor binds only to the ________ and not to the _________ and competes with the substrate for the __________

Enzyme, enzyme-substrate complex, active site

13

A competitive inhibitor _________ Km.

Increases

14

An uncompetitive inhibitor binds to the enzyme in a place other than the __________ and only to the _________

Active site; enzyme-substrate complex

15

Uncompetative inhibitors ________ Vmax

decreases

16

Mixed inhibitor binds outside the ________ but can bind to either the ________ or __________

Active site, Enzyme; Enzyme-Substrate complex

17

Penicillin is an example of an ____________

Irreversible inhibitor

18

Allosteric regulation of an enzyme

Binding of another molecule changes the conformation of the enzyme and alters function; usually involves feedback loops

19

Covalent modification of an enzyme

Involves phosphorylation and is in response to intra/extra cellular signals

20

Proteolytic cleavage on an enzyme

Once an enzyme is cleaved into a smaller segment, it is activated

21

What are the four types of enzymatic regulators?

Allosteric, Covalent, Binding of another regulatory protein, Proteolytic cleavage