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Flashcards in Biology Part. 1 Deck (21):
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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.

Active site

1

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).

Active Transport

2

Main energy source for cells.

Adenosine triphosphate

3

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

Aquaporin

4

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).

Cellular Respiration

5

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

Chemical Energy

6

An organic molecule serving as a cofactor. Most vitamins function as coenzymes in important metabolic reactions.

Coenzyme

7

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

Cofactor

8

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

Competitive Inhibitor

9

An increase or decrease in the density of a chemical substance in an area.

Concentration Gradient

10

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

Diffusion

11

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.

Endergonic Reaction

12

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

Endocytosis

13

The capacity to perform work, or to rearrange matter.

Energy

14

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

Energy Coupling

15

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

Entropy

16

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

Enzyme

17

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.

Exergonic Reaction

18

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

Exocytosis

19

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

Facilitated diffusion

20

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

Feedback Inhibition