Metabolism

Question 1

metabolism

Answer 1

the collection of chemical reactions that occur in an organism

Question 2

metabolic pathways

Answer 2

a series of chemical reactions occuring in a cell

Question 3

negative feedback

Answer 3

regulation of a biochemical pathway achieved when a reaction product inhibits and earlier step in the pathway, common

Question 4

positive feedback

Answer 4

a regulation mechanism in which an accumulation of an end product of a processes speeds up that process, less common

Question 5

enzyme

Answer 5

a protein or RNA that catalyzes a specific chemical reaction by lowering the activation energy

Question 6

substrate

Answer 6

the reactant an enzyme acts on

Question 7

active site

Answer 7

the region of an enzyme surface that binds the substrate molecule and catalytically transformis it

Question 8

induced fit

Answer 8

a change in the conformation of an enzyme in response to substrate binding that renders the enzyme catalytically active

Question 9

catabolic

Answer 9

breaking molecules down; releasing energy

Question 10

anabolic

Answer 10

building molecules up; consuming energy

Question 11

exergonic

Answer 11

spontaneous chemical reaction; a decrease in free energy

Question 12

endergonic

Answer 12

nonspontaneous chemical reaction; an increase in free energy

Question 13

fermentation

Answer 13

a catabolic process that does not require oxygen

Question 14

aerobic respiration

Answer 14

a catabolic process that requires oxygen; more prevalent and efficient than fermentation

Question 15

cellular respiration

Answer 15

taking organic compounds and catabolizing them via enzymes to release energy

Question 16

NAD+ and NADH

Answer 16

NAD+ is a coenzyme that carries electrons from one reaction to another; NAD+ accepts electrons (low energy state) and NADH donates electrons (high energy state)

Question 17

FAD and FADH2

Answer 17

similar to NAD+ and NADH, a coenzyme that carries electrons; FAD accepts electrons (low energy state) and FADH2 donates electrons (high energy state)

Question 18

coenzyme

Answer 18

“helper molecule,” a non-protein chemical compound that is required for the protein’s/enzyme’s biological activity

Question 19

steps of aerobic respiration

Answer 19

glycolysis > pyruvate oxidation > citric acid cycle (Krebs/TCA) > oxidative phosphorylation

Question 20

glycolysis

Answer 20

process that breaks down glucose into 2 pyruvate and produces 2 ATP and 2 NADH

Question 21

pyruvate oxidation

Answer 21

if oxygen is present, process that breaks down 2 pyruvate into 2 acetyl-CoA and produces 2 NADH, feeds into citric acid cycle

Question 22

citric acid cycle

Answer 22

process that uses 2 acetyl-CoA and produces 2 ATP, 6 NADH, and 2FADH2, feeds into electron transport

Question 23

oxidative phosphorylation

Answer 23

electron transport chain and chemiosmosis

Question 24

electron transport chain

Answer 24

process that oxidizes NADH to NAD+ and FADH2 to FADH, creating a H+ (proton) gradient across the inner mitochondrial membrane, feeds into chemiosmosis

Question 25

chemiosmosis

Answer 25

ATP synthesis powered by the flow of H+ (protons) back across the membrane

Question 26

ATP

Answer 26

adenosine triphosphate; a phosphate group donor in the cell energy cycle; carries chemical energy between metabolic pathways by serving as a shared intermediate coupling endergonic and exergonic reactions

Question 27

energy coupling

Answer 27

the transfer of energy from one process to another (ATP is normally involved)

Question 28

phosphorylated intermediate

Answer 28

the recipient of the phosphate group from ATP; makes a higher energy, less stable molecule