enzymes

Question 1

activation energy

Answer 1

activation energy is the minimum amount of energy required to achieve a successful collision, the amount of activation energy determines the rate of reaction the higher the energy the slower the reaction

Question 2

enzymes

Answer 2

catalysts that increase the rate of reaction by lowering activation energy

Question 3

binding region of enzyme

Answer 3

substrates bind to the active site, and the specificity of it allows for the enzyme to bind to the correct substrate

Question 4

enzyme- substrate complex

Answer 4

a temporary molecule formed when the substrate binds to the enzyme

Question 5

induced fit

Answer 5

when the substrate enters the active site the active site changes shapes slightly to create a tighter fit

Question 6

anabolic reactions

Answer 6

synthesise larger substrates, required energy to form bonds

Question 7

catabolic reactions

Answer 7

larger molecules are broken down. This releases energy as bonds are broken

Question 8

anabolic reactions and enzymes

Answer 8

enzymes lower the activation energy of anabolic reactions by brining substrates and enzymes close together

Question 9

catabolic reactions and enzymes

Answer 9

enzymes lower the activation energy of catabolic reactions by stressing the bond between the enzyme and substrate

Question 10

factors affecting rate of enzyme catalysed reaction

Answer 10

temperature, pH, the concentration of enzymes, substrates and products and the presence of inhibitors

Question 11

temperature

Answer 11

the reaction is greatest a the optimum temperature, and increases kinetic energy increasing number of collisions, above the optimum temperature the enzyme becomes denatures and the active site becomes not complementary to the substrate

Question 12

pH

Answer 12

optimum pH is when the reaction is greatest, changes in the ph limit the formation of enzyme substrate complexes

Question 13

enzyme concentration

Answer 13

rate of reaction is low when enzyme concentration is low, the rate increases when enzyme concentration increases, it becomes constant when the number of substrates is less than the number of avaliable enzymes

Question 14

substrate concentration

Answer 14

rate of reaction is low when substrate concentration is low and there are more enzymes than substrate, the rate of reaction increases as substrate concentration increases as more substrates occupy active sites, the rate becomes constant as the number of enzymes is less than the number of substrates

Question 15

product concentration

Answer 15

inhibited when the concentration of products become too high in a cell

Question 16

enzyme co-factors

Answer 16

small molecules or ions that activate enzymes or transfer important molecules to the active site

Question 17

co-enzyme

Answer 17

are vitamins that bind temporarily with an enzyme and support its function

Question 18

inorganic ions

Answer 18

are activators which are inorganic metal ions, that alter the charge of the active site which improves binding

Question 19

prosthetic group

Answer 19

bind permanently to an enzyme molecule

Question 20

inhibitors

Answer 20

inactivates the enzymes, and can be reversible or irreversible

Question 21

examples of inhibitors

Answer 21

heavy metals, cyanide

Question 22

competitive inhibitors

Answer 22

interferes with active site of enzyme so substrate cannot bind

Question 23

noncompetitive inhibitor

Answer 23

changes shape of enzyme so it cannot bind to substrate as they no longer have complementary shapes