RP01 - Rate of enzyme controlled reactions

Question 1

What four factors effect enzyme activity

Answer 1

Enzyme conc
Substrate conc
Temperature
pH

Question 2

How is a control set up in a practical measuring enzyme activity

Answer 2

Replace the enzyme solution with distilled water OR boiled enzyme solution

Question 3

How can the results of the practicals measuring enzyme activity be used to find the initial rate of reaction

Answer 3

• Plot graph with rate of reaction against time
• Draw a tangent at time = 0 to find initial rate

Question 4

Outline the practical procedure used to measure the effect of temperature on enzyme activity, using trypsin and milk

Answer 4

• Put test tubes with equal volume of trypsin and milk in different test tubes, in a water bath for 5 minutes for temperature to equilibrate
• Mix together and immediately start timing, record the time taken for the milk to be completely hydrolysed
• Do this for five different temperatures with MULTIPLE REPEATS

Question 5

How is rate of reaction calculated from time

Answer 5

Rate of reaction = 1/time

Question 6

What is the risk and level of risk associated with handling enzymes

Answer 6

• Students may have allergic reactions to enzymes, so avoid contact with skin and wear eye protection
• Low risk