Biology lab experiments and methods

¶ … Temperature on Enzyme Activity

Tube 2, #4: Place the tube in an incubator (or water bath) at 37 degree centigrade. After 15 minutes, what change do you now observe?

After 15 minutes the milk became partially solid.

Tube 3, #4: Add three drops of warmed rennin and return the tube to an incubator (or water bath) at 37 degree centigrade. After 15 minutes, what change do you now observe?

After 15 minutes, the milk remains liquid with no solidifying taking place.

Table 5.1 Rennin Experiment

Tube Results Explanation

Refrigerated rennin - (tube 2) 0 Enzyme not active at low temperature.

Warmed rennin - (tube 1) ++ Enzyme effective at 37c temperature.

Boiled rennin - (tube 3) 0 Enzyme not active at high temperature,

Enzyme denatured at high temperature.

Graph: Effect of Temperature on Enzyme Activity.

Laboratory Review

What happens at the active site of an enzyme?

The active site is the region of the enzyme where the substrate binds and where the chemical reaction takes place.

2. On the basis of the active site, explain why the following conditions speed a chemical reaction.

a. More enzyme. With more enzyme, there are more active sites for substrates to bind to, meaning that more substrate molecules react more quickly.

b. More substrate. With more substrate, enzyme comes into contact with substrate more quickly, speeding the reaction.

3. Based on the experimental procedures you performed, name three other conditions (other than the ones mentioned in number 2) that maximize enzymatic reactions.

A. Temperature of the environment.

B. Temperature of the enzyme.

C. Initial temperature of the substrate.

4. Explain the necessity for each of the three conditions you listed in number 3.

A. As was observed in the experiment, placing the substrate in an environment at 37c maximized the reaction (observed when placing refridgerated milk in the water bath). This shows how enzymes work best at a certain preferred temperature.