AQA GCSE Biology Enzymes Flashcards
(11 cards)
What is the independent variable?
pH of the solution
What is the dependent variable?
Rate of the reaction
State two control variables
. Volume of amylase solution
. Concentration of the substrate
State two hazards and precautions
. Strong acids or alkalis can get onto the skin- Wear gloves
. Hot equipment- Wear heat-resistant gloves
Why do you need to add a drop of iodine solution to every well of a spotting tile?
To test for the presence of starch
How do you know when starch is no longer present?
When the iodine solution remains browny-orange
Why do you have to change syringes?
To avoid cross-contamination of substances
Why is pH5 used?
It’s the optimum pH for many enzymes such as amylase to work effectively
Why is the water heated until its 35.C?
35.C is close to the optimum temperature for enzymes but not too high that it denatures the enzyme.
State two ways this investigation can be improved
. Increase temperature range
. Keep the temperature of the water constant throughout the experiment
What is the purpose of this investigation?
To investigate the effect of pH on enzyme activity
