Enzyme terminology

Question 0

substrate

Answer 0

the compound on which the enzyme works

Question 1

Enzyme

Answer 1

a macromolecule serving as a catalyst, chemical agent that increases the rate of a reaction without being consumed by the reaction. most enzymes are protiens.

Question 2

active site

Answer 2

the specific portion of the enzyme to which the substrate binds during reaction

Question 3

activation

Answer 3

any process that makes an inactive enzyme (ex. addition of a cofactor or cleavage of a polypeptide chain.)

Question 4

Inhibition

Answer 4

any process that makes an active enzyme less active

Question 5

inhibitor

Answer 5

an agent which inhibits enzymes

Question 6

reversible inhibitor

Answer 6

goes on and off, allowing the enzyme to regain activity when the inhibitor leaves

Question 7

irreversible inhibitor

Answer 7

destroys enzyme activity, usually by bonding with side-chain groups in the active site

Question 8

competitive inhibition

Answer 8

competition between an inhibitor and substrate of similar structure for the active site of the enzyme

Question 9

non-competitive inhibition

Answer 9

inhibitor binds to enzyme at a location other than the active site and deactivates the enzyme

Question 10

feedback inhibition

Answer 10

when the concentration of a product several steps down the line builds up enough to inhibit an earlier enzyme stopping the reaction

  - when concentration of product D is low, then the rxn can proceed
  - when the concentration of product D accumulates, then D tells            enzyme E1 to shut down.

Question 11

allosteric control

Answer 11

the binding at one site of an enzyme influences (activates of deactivates) the shape of the active site

Question 12

negative moldulation

Answer 12

allosteric control

-if this inhibits enzyme action

Question 13

positive modulation

Answer 13

allosteric control

-if this stimulates enzyme action

Question 14

isoenzymes

Answer 14

different forms of the same enzyme

Question 15

proenzyme

Answer 15

biologically inactive form of an enzyme

Question 16

regulator

Answer 16

sometimes called modulator- is the compound which binds to the regulatory site on the enzyme-allosteric enzyme action is controlled by the modulator

Question 17

lock and key theory

Answer 17

active site in an enzyme has a fixed, rigid shape. only substrates with a complementary geometry can fit

Question 18

induced-fit model

Answer 18

active site in an enzyme can undergo small changes in shape in order to accommodate a substrate

Question 19

ligand

Answer 19

the molecule that bind to a receptor

Question 20

cofactors

Answer 20

some enzymes are made up only of polypeptide chains, but some have non protein portions. cofactors may be metal ions of organic molecules

Question 21

apoenzyme

Answer 21

the protein portion of a cofactor

Question 22

coenzyme

Answer 22

the organic cofactor that binds with an apoenzyme to give an active enzyme