factors affecting activity

Question 1

name the 5 factors that affect the rate of enzyme controlled reactions

Answer 1

• enzyme concentration
• substrate concentration
• concentration of inhibitors
• pH
• temperature

Question 2

how does substrate concentration affect rate of reaction? draw this on a graph

Answer 2

• given that enzyme concentration is fixed, rate increases proportionally to substrate concentration
• rate levels off when maximum number of ESC’s form at any given time
• (refer to images)

Question 3

how does enzyme concentration affect rate of reaction? draw this on a group

Answer 3

• given that substrate is in excess, rate increases proportionally to enzyme concentration
• rate may level off if maximum number of ESC’s form at any given time
• (refer to images)

Question 4

how doe temperature affect the rate of enzyme controlled reactions? draw this on a graph

Answer 4

• rate increases as kinetic energy increases and peaks at optimum temperature
• above optimum, ionic and H-bonds in tertiary structure break = active site no longer complementary to substrate (denaturation)
• (refer to image)

Question 5

what is temperature coefficient?

Answer 5

Q10: measures change in rate of reaction per 10°C temperature increase
Q10 = R2 / R1 (where R represents rate)

Question 6

how does pH affect rate of reaction? draw this on a graph

Answer 6

• enzymes have a narrow optimum pH range
• outside range, H+/ OH- ions interact with H-bonds and ionic bonds in tertiary structure = denaturation