Chapter 5 Pt 1

Question 1

The part of an enzyme molecule where a substrate molecule attaches (by means of weak chemical bonds); typically, a pocket or groove on the enzyme’s surface.

Answer 1

Active site

Question 2

The movement of a substance across a biological membrane against its concentration gradient, aided by specific transport proteins and requiring input of energy (often as ATP).

Answer 2

Active transport

Question 3

Main energy source for cells

Answer 3

Adenosine triphosphate (ATP)

Question 4

A transport protein in the plasma membrane of some plant or animal cells that facilitates the diffusion of water across the membrane (osmosis).

Answer 4

Aquaporin

Question 5

The aerobic harvesting of energy from food molecules; the energy-releasing chemical breakdown of food molecules, such as glucose, and the storage of potential energy in a form that cells can use to perform work; involves glycolysis, the citric acid cycle, and oxidative phosphorylation (the electron transport chain and chemiosmosis).

Answer 5

Cellular respiartion

Question 6

Energy available in molecules for release in a reaction; a form of potential energy.

Answer 6

Chemical energy

Question 7

An organic molecule serving as a co-factor. Most vitamins function in this form in important metabolic reactions.

Answer 7

Coenzymes

Question 8

A non-protein molecule or ion that is required for the proper functioning of an enzyme. See also coenzyme.

Answer 8

Co-factor

Question 9

A substance that reduces the activity of an enzyme by binding to the enzyme’s active site in place of the substrate. This structure mimics that of the enzyme’s substrate.

Answer 9

Competitive inhibitor

Question 10

The process of particles, which are sometimes called solutes, moving through a solution or gas from an area of higher number of particles to an area of lower number of particles. The areas are typically separated by a membrane.

Answer 10

Concentration gradient

Question 11

The spontaneous tendency of a substance to move down its concentration gradient from where it is more concentrated to where it is less concentrated.

Answer 11

Diffusion

Question 12

An energy-requiring chemical reaction, which yields products with more potential energy than the reactants. The amount of energy stored in the products equals the difference between the potential energy in the reactants and that in the products.

Answer 12

Endergonic reaction

Question 13

Cellular uptake of molecules or particles via formation of new vesicles from the plasma membrane

Answer 13

Endocytosis

Question 14

The capacity to perform work, or to rearrange matter.

Answer 14

Energy

Question 15

In cellular metabolism, the use of this form is released from an exergonic reaction to drive an endergonic reaction.

Answer 15

Energy coupling

Question 16

A measure of disorder. One form of disorder is heat, which is random molecular motion

Answer 16

Entropy

Question 17

A protein that serves as a biological catalyst, changing the rate of a chemical reaction without itself being changed into a different molecule in the process.

Answer 17

Enzyme

Question 18

An energy-releasing chemical reaction in which the reactants contain more potential energy than the products. The reaction releases an amount of energy equal to the difference in potential energy between the reactants and the products.

Answer 18

Exergonic reaction

Question 19

The movement of materials out of the cytoplasm of a cell by the fusion of vesicles with the plasma membrane.

Answer 19

Exocytosis

Question 20

The passage of a substance through a specific transport protein across a biological membrane down its concentration gradient.

Answer 20

Facilitated diffusion

Question 21

A method of metabolic control in which a product of a metabolic pathway acts to stop an enzyme within that pathway.

Answer 21

Feedback inhibition