Midterm II -- Ch. 8 - Metabolism

Question 1

Metabolism

Answer 1

The totality of an organism’s chemical reactions.

Question 2

metabolic pathway

Answer 2

a series of chemical reactions that either builds a complex molecule (anabolic pathway) or breaks down a complex molecule (catabolic pathway).

Question 3

catabolic pathways

Answer 3

metabolic pathways that release energy by breaking down complex molecules to simpler compounds

Question 4

anabolic pathways

Answer 4

consume energy to build complicated molecules from simpler ones; aka biosynthetic pathways.

Question 5

kinetic energy

Answer 5

energy that can be associated with the relative motion of objects.

Question 6

heat/thermal energy

Answer 6

kinetic energy associated w/ the random movement of molecules or atoms.

Question 7

potential energy

Answer 7

energy that is not kinetic; energy that matter posses b/c of its location or structure.

Question 8

chemical energy

Answer 8

potential energy available for release in a chemical reaction.

Question 9

thermodynamics

Answer 9

the study of energy transformations that occur in a collection of matter.

Question 10

first law of thermodynamics

Answer 10

the energy of the universe is constant; Energy can be transferred and transformed, but it cannot be created or destroyed.”

Question 11

entropy

Answer 11

a quantity used as a measure of disorder or randomness.

Question 12

second law of thermodynamics

Answer 12

the more randomly arranged a collection of matter is, the greater its entropy; “every energy transfer or transformation increases the entropy of the universe.”

Question 13

spontaneous process

Answer 13

a process that can occur w/p an input of energy.

Question 14

free energy

Answer 14

the portion of a biological system’s energy that can perform work when temperature and pressure are uniform throughout the system.
know Gibbs free energy formula

Question 15

exergonic reaction

Answer 15

“energy outward”; a spontaneous chemical reaction, in which there is a net release of free energy.

Question 16

endergonic reaction

Answer 16

“energy inward”; a reaction that absorbs free energy from its surroundings.

Question 17

energy coupling

Answer 17

the use of an exergonic process to drive an endergonic one.

Question 18

ATP (adenosine triphosphate)

Answer 18

an adenine-containing nucleoside triphosphate that releases free energy when its phosphate bonds are hydrolyzed; this energy is used to drive endergonic reactions in cells.

Question 19

phosphorylated intermediate

Answer 19

a molecule (often a reactant) w/ a phosphate group covalently bound to it, making it more reactive (less stable) than the unphosphorylated molecule.

Question 20

enzyme

Answer 20

a macromolecule that catalyses/increases the rate of a reaction w/o being consumed by the reaction; most are proteins

Question 21

catalyst

Answer 21

chemical agent that selectively increases the rate of a reaction w/o being consumed by the reaction.

Question 22

activation energy

Answer 22

the initial investment of energy for starting a reaction; the energy required to contort the reactant molecules so the bonds can break; “free energy of activation.”

Question 23

substrate

Answer 23

the reactant an enzyme reacts on.

Question 24

enzyme-substrate complex.

Answer 24

formed when an enzyme binds to its substrates, (when there are two or more reactants).

Question 25

active site

Answer 25

a restricted region of the enzyme molecule that binds to the substrate; typically a pocket or groove on the surrounding face of the enzyme where catalysis occurs.

Question 26

induced fit

Answer 26

caused by the entry of the substrate, the change in shape of the active site of an enzyme so that it binds more snugly to the substrate.

Question 27

cofactors

Answer 27

nonprotein helpers for catalytic activity.

Question 28

coenzyme

Answer 28

a cofactor that is an organic molecule.

Question 29

competitive inhibitors

Answer 29

a substance that reduces the activity of an enzyme by entering the active site in place of the substrate, whose structure it mimics.

Question 30

noncompetitive inhibition

Answer 30

impede enzymatic reactions by binding to another part of the enzyme, NOT to the active site.

Question 31

allosteric regulation

Answer 31

a case in which a protein's function at one site is affected by the binding of a regulatory molecule to a separate site.

Question 32

cooperativity

Answer 32

mechanism that amplifies the response of enzymes to substrates. ---- a kind of allosteric regulation whereby a shape change in one subunit of a protein caused by substrate binding is transmitted to all other subunits, facilitating binding of additional substrate molecules to those subunits.

Question 33

feedback inhibition

Answer 33

a method of metabolic control in which the end product of a metabolic pathway acts as an inhibitor of an enzyme within that pathway.