Core Practical 4 - Enzymes

Question 1

What is the aim of this experiment

Answer 1

To see how the rate of reaction changes when substrate concentration is fixed abd enzyme concentration changes

Question 2

Describe the method to the enzyme practical

Answer 2

Step 1- Set up the aparatus:
Attach the delivery tube to the bung, and attach a gas syringe to the end (or place it into water held down by a weight and into a measuring cylinder).
Add 5cm3 hydrogen peroxide + buffer solution to the conical flask.

Step 2:
Cut up 1mm discs of potato using a knife + cork borer and add 5 to the conical flask

Step 3: place the bung on the conical flask immediately and start a timer.

Step 4:
every minute for 5 minutes record the volume of gas produced in the measuring cylinder / gas syringe

Step 5:
Clean out the conical flask and repeate the experiment with varying levels of enzyme concentration, by using more potato discs.

Question 3

Why does increasing the number of potato discs increase the rate of reaction / volume of oxygen produced

Answer 3

As more potatoes are added, more oxygen is produced (faster) because more enzymes are present.

There is an increase in oxygen volume, due to an increase in potato surface area

The volume of oxygen produced will eventually level off when all the substrate is used up (the substrate may be a limiting factor)