Unit 2 Key Area 1

Question 1

Difference that exists between two regions resulting in diffusion.

Answer 1

Concentration gradient

Question 2

Step in metabolic pathway that can operate in both a forward and backward direction.

Answer 2

Reversable

Question 3

Movement of molecules or ions through a cell membrane form a region of lower concentration to a region of higher concentration.

Answer 3

Active transport

Question 4

Movement of molecules or ions through a cell membrane from a region of higher concentration to a region of lower concentration.

Answer 4

Diffusion

Question 5

Type of metabolic pathway that brings about the biosynthesis of complex molecules and requires energy.

Answer 5

Anabolism

Question 6

Type of metabolic pathway that brings about the breakdown of complex molecules and releases energy.

Answer 6

Catabolism

Question 7

Type of protein molecule in a cell membrane containing a pore through which specific substances are able to diffuse.

Answer 7

Channel-forming

Question 8

Type of protein molecule that actively pumps specific ions into/out of a cell.

Answer 8

Carrier

Question 9

Step(s) in a metabolic pathway that allow the regular steps to be bypassed.

Answer 9

Alternative route

Question 10

Sum of all the biochemical reactions occurring within a living organism.

Answer 10

Metabolism

Question 11

Substance that increases the rate of a chemical reaction and remains unaltered by the reaction.

Answer 11

Catalyst

Question 12

Complementary relationship of a molecular structure allowing an enzyme to combine with one type of substrate only.

Answer 12

Specificity

Question 13

Substance formed as a result of of an enzyme acting on its substrate.

Answer 13

End product

Question 14

Substance upon which an enzyme acts, resulting in the formation on an end product

Answer 14

Substrate

Question 15

Energy needed to break the chemical bonds in the reactants in a chemical reaction.

Answer 15

Activation energy

Question 16

Region in an enzyme molecule where the complementary surface of its substrate molecule becomes attached.

Answer 16

Active site

Question 17

Degree of chemical attraction between reactant molecules.

Answer 17

Affinity

Question 18

State of reactant molecules that have absorbed enough energy to break their bonds and allow the reaction to occur.

Answer 18

Transition

Question 19

Protein made by living cells that acts as a biological catalyst.

Answer 19

Enzyme

Question 20

State of close molecular contact resulting from change in shape of an enzyme’s active site to accommodate its substrate.

Answer 20

Induced fit

Question 21

Way in which molecules of two reactants are held together as determined by the shape of the enzymes active site.

Answer 21

orientation

Question 22

Amount of chemical change that occurs per unit time

Answer 22

Reaction rate

Question 23

Process by which a metabolite at a later stage in a pathway builds up and prevents the activity of an enzyme controlling an earlier stage

Answer 23

Feedback inhibition

Question 24

Type of inhibitor that becomes attached to a non-active site on an enzyme and changes the enzymes molecular shape.

Answer 24

non-competitive

Question 25

Region on an enzyme molecule to which the complementary surface molecule becomes attached.

Answer 25

Active site

Question 26

Type of inhibitor with a molecular structure similar to an enzymes substrate enabling it to become attached to the enzymes active site.

Answer 26

Competitive

Question 27

Regulatory molecule that halts or decreases the rate of an enzyme-controlled reaction

Answer 27

inhibitor