B1.1.4 Enzymes

Question 1

collision theory states that

Answer 1

for reactants to react into products they must collide with enough energy and in the correct orientation

Question 2

what 4 factors affect the rate of reaction

Answer 2

temperature, pressure (only in gases), concentration, catalysts

Question 3

how does temperature affect rate of reaction

Answer 3

greater temperature = greater average kinetic energy = more collisions = greater rate of reaction

Question 4

how does concentration affect rate of reaction

Answer 4

greater concentration = more reactants = more collisions = greater rate of reaction

Question 5

how do enzymes affect rate of reaction

Answer 5

enzymes lower activation anergy by bringing reactants in closer proximity = greater rate of reaction

Question 6

enzymes are

Answer 6

globular proteins and biological catalysts

Question 7

lock and key theory states

Answer 7

that the substrate fits into the active site perfectly

Question 8

induced fit theory states

Answer 8

that the substrate induces the active site into changing shape to fit the substrate

Question 9

enzyme + substrate =

Answer 9

Enzyme substrate complex

Question 10

the 5 factors that affect enzyme controlled reactions are

Answer 10

temperature, pH, substrate concentration, enzyme concentration, inhibitors

Question 11

the highest rate of reaction for an enzyme is known as its

Answer 11

optimum

Question 12

how do lower than optimal temperatures affect enzymes

Answer 12

lower rate due to collision theory, enzyme unnafected

Question 13

how do higher than optimal temperature affect enzymes

Answer 13

bonds may be broken in the tertiary structure - active site changes shape - reduced ability to make enzyme substrate complexes

Question 14

how do higher or lower than optimal pH values affect enzymes

Answer 14

bonds may be broken in the tertiary structure - active site changes shape - reduced ability to make enzyme substrate complexes

Question 15

High temperatures and extremes of pH may cause what

Answer 15

the enzyme to denature

Question 16

what does denature mean

Answer 16

a permenant change in the enzymes structure

Question 17

a competative inhibitor works by

Answer 17

bonding in the same place as the substrate

Question 18

a non-competative inhibitor works by

Answer 18

not bonding to the active site but changing the shape of it preventing substrate binding

Question 19

competative reversible inhibitors

Answer 19

bind active sites but unbind easily

Question 20

competative ireversible inhibitors

Answer 20

bind the active site permenantly

Question 21

non-competative irreversible inhibitors

Answer 21

bind the enzyme permenantly preventing substrate binding

Question 22

non-competative ireversible inhibitors

Answer 22

bind the enzyme preventing substrate binding

Question 23

the effect of increasing substrate concentration with competative inhibitors present is

Answer 23

the rate is reduced initially but eventually reaches optimal as the effect of the inhibitor is reduced due to the presentce of more substrate

Question 24

the effect of increasing substrate concentration with non-competative inhibitors present is

Answer 24

the rate of reaction is reduced

Question 25

which line shows what would happen if a non-competative inhibitor was present

Answer 25

line 2

Question 26

which line shows what would happen if a competative inhibitor was present

Answer 26

line 1