Chapter Four - Energy and Enzymes

Question 1

Kinetic Energy

Answer 1

The energy of motion.

Question 2

Potential Energy

Answer 2

Stored energy.

Question 3

Thermodynamics

Answer 3

The study of the energy flow during chemical and physical reactions.

Question 4

The First Law of Thermodynamics

Answer 4

Energy can be transformed from one form into another or transferred from one place to another, but it cannot be created nor destroyed.

Question 5

The Second Law of Thermodynamics

Answer 5

The total disorder (entropy) of a system and its surroundings always increases.

Question 6

Entropy

Answer 6

Disorder, in thermodynamics.

Question 7

Spontaneous Reactions

Answer 7

Chemical or physical reaction that occurs without outside help.

Question 8

Enthalpy

Answer 8

Potential energy in a system.

Question 9

Endothermic

Answer 9

Reactions that absorb heat energy.

Question 10

Exothermic

Answer 10

Processes that release heat energy.

Question 11

Free Energy

Answer 11

The energy in a system that is available to do work.

Question 12

Exergonic

Answer 12

Reaction that has a negative total G because it releases free energy.

Question 13

Endergonic

Answer 13

Reaction that can proceed only if free energy is supplied.

Question 14

Catabolic Pathways

Answer 14

Type of metabolic pathway in which energy is released by the breakdown of complex molecules to simpler compounds.

Question 15

Anabolic Pathways

Answer 15

Type of metabolic pathway in which energy is consumed to build complicated molecules from simpler ones, often called a biosynthetic pathway.

Question 16

Adenosine Triphosphate (ATP)

Answer 16

The primary agent that coupes exergonic and endergonic reactions.

Question 17

Energy Coupling

Answer 17

The process by which ATP is brought in close contact with a reactant molecule involve in an endergonic reaction, and when the ATP is hydrolyzed, the terminal phosphate group is transferred to the reactant molecule.

Question 18

Activation Energy

Answer 18

The initial input of energy required to start a reaction.

Question 19

Enzyme

Answer 19

Protein that accelerates the rate of a cellular reaction.

Question 20

Active Site

Answer 20

The region of an enzyme that recognizes and combines with a substrate molecule.

Question 21

Cofactor

Answer 21

An inorganic or organic nonprotein group that is necessary for catalysis to take place.

Question 22

Coenzymes

Answer 22

Organic cofactors that include complex chemical groups of various kinds.

Question 23

Competitive Inhibition

Answer 23

Inhibition of an enzyme reaction by an inhibitor molecule that resembles the normal substrate closely enough so that it fits into the active site of the enzyme.

Question 24

Non-Competitive Inhibition

Answer 24

Inhibition of an enzyme reaction by an inhibitor molecule that binds to the enzyme at a site other than the active site and does not compete directly with the substrate for binding to the active site.

Question 25

Allosteric Regulation

Answer 25

specialized control mechanism for enzymes with an allosteric site, a regulatory site outside the active site that may either slow or accelerate activity depending on the enzyme.

Question 26

Allosteric Site

Answer 26

A regulatory site outside of the active site.

Question 27

Allosteric Inhibitor

Answer 27

Molecule that converts an enzyme with an allosteric site, a regulatory site outside of the active site, from the active form to the inactive form.

Question 28

Feedback Inhibition

Answer 28

In enzyme reactions, regulation in which the product of a reaction acts as a regulator of the reaction. Also referred to as end-product inhibitor.

Question 29

Hydrolysis

Answer 29

Any chemical reaction in which a molecule of water ruptures one or more chemical bonds. The term is used broadly for substitution, elimination, and solvation reactions in which water is the nucleophile.

Question 30

Nucleophile

Answer 30

A chemical species that donates an electron pair to form a chemical bond in relation to a reaction.

Question 31

Phosphorylation

Answer 31

A biochemical process that involves the addition of phosphate to an organic compound.

Question 32

Denaturation

Answer 32

A loss of both the structure and function of a protein due to extreme conditions that unfold it from its conformation.