RP1 Rate Of An Enzyme Controlled Reaction

Question 1

What are factors that affect enzyme activity?

Answer 1

1. Enzyme concentration
2. Substrate concentration
3. Temperature
4. 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 result of the practical measuring enzyme activity be used to the the initial rate of reaction?

Answer 3

Plot your results on a graph of “rate of reaction” against “time”.

Draw a tangent at time= 0 to find the initial rate

Question 4

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

Answer 4

Immerse equal volumes of trypsin and milk, stored in different test tubes, in water-bath for 5 minuets for the temperature to equilibrate.

Mix together and immediately start timing, record the time taken for the milk to be completely hydrolysed (become colourless)

Test at least 5 temperatures, with least 3 repeats at each temperature.

Question 5

How is the rate of reaction calculated from time?

Answer 5

Rate of reaction= 1/time

Question 6

What is the effect of temperature on enzyme activity?

Answer 6

As temperature increase, kinetic energy increases so more ES complex form. Rate of reaction increases up to optimum temperature.

Beyond that, bonds in the tertiary structure of enzyme break, changes the shape of active site. The substrate and enzyme are no longer complementary, so rate of reaction decreases.

Question 7

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

Answer 7

Students may have an allergic reaction to enzyme, so avoid contact with eyes or skin, and wear eye protection.

Low risk