Metabolism Key Terms

Question 1

activation energy

Answer 1

energy necessary for reactions to occur

Question 2

active site

Answer 2

specific region of the enzyme to which the substrate binds

Question 3

allosteric inhibition

Answer 3

inhibition by a binding event at a site different from the active site, which induces a conformational change and reduces the affinity of the enzyme for its substrate

Question 4

anabolic

Answer 4

(also, anabolism) pathways that require an input of energy to synthesize complex molecules from simpler ones

Question 5

ATP

Answer 5

adenosine triphosphate, the cell’s energy currency

Question 6

bioenergetics

Answer 6

study of energy flowing through living systems

Question 7

catabolic

Answer 7

(also, catabolism) pathways in which complex molecules are broken down into simpler ones

Question 8

chemical energy

Answer 8

potential energy in chemical bonds that is released when those bonds are broken

Question 9

coenzyme

Answer 9

small organic molecule, such as a vitamin or its derivative, which is required to enhance the activity of an enzyme

Question 10

competitive inhibition

Answer 10

type of inhibition in which the inhibitor competes with the substrate molecule by binding to the active site of the enzyme

Question 11

denature

Answer 11

process that changes the natural properties of a substance

Question 12

endergonic

Answer 12

describes chemical reactions that require energy input

Question 13

energy coupling

Answer 13

process during which energy released by one reaction is used to drive another reaction

Question 14

entropy

Answer 14

measure of randomness or disorder within a system

Question 15

exergonic

Answer 15

describes chemical reactions that release free energy

Question 16

feedback inhibition

Answer 16

effect of a product of a reaction sequence to decrease its further production by inhibiting the activity of the first enzyme in the pathway that produces it

Question 17

free energy

Answer 17

Gibbs free energy is the usable energy, or energy that is available to do work.

Question 18

heat

Answer 18

energy energy transferred from one system to another that is not work (energy of the motion of molecules or particles)

Question 19

induced fit

Answer 19

dynamic fit between the enzyme and its substrate, in which both components modify their structures to allow for ideal binding

Question 20

kinetic energy

Answer 20

type of energy associated with objects or particles in motion

Question 21

metabolism

Answer 21

all the chemical reactions that take place inside cells, including anabolism and catabolism

Question 22

phosphoanhydride bond

Answer 22

bonds that connect phosphates in an ATP molecule

Question 23

potential energy

Answer 23

type of energy that has the potential to do work; stored energy

Question 24

substrate

Answer 24

molecule on which the enzyme acts

Question 25

thermodynamics

Answer 25

study of energy and energy transfer involving physical matter

Question 26

transition state

Answer 26

high-energy, unstable state (an intermediate form between the substrate and the product) occurring during a chemical reaction