Investigating Enzymes Flashcards Preview

EDEXCEL iGCSE Biology > Investigating Enzymes > Flashcards

Flashcards in Investigating Enzymes Deck (4)
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1
Q

When investigating the affect of temperature on enzyme activity what could you measure?

A

How fast a product appears How fast a substrate disappears

2
Q

How would you measure how fast a product appears?

A
  1. The enzyme catalase (potato) catalyses the breakdown of hydrogen peroxide into water and oxygen.
  2. Collect and measure how much oxygen is produced in a set time.
  3. Use a pipette to add a set amount of hydrogen peroxide to a boiling tube. Put the tube in a water bath at 10*c.
  4. Add 1cm3 catalase (potato) to hydrogen peroxide and quickly attach a bung.
  5. Record how much oxygen is produced in the first minute. Repeat 3 times and calculate the mean.
  6. Repeat at 20*c, 30*c & 40*c
  7. Control any variables e.g. pH, the potato used, size of potato pieces etc. To make it a fair test.
3
Q

How would you measure how fast a substrate disappears?

A
  1. The enzyme amylase catalyses the breakdown of starch to maltose.
  2. It’s easy to detect starch using iodine solution- if starch is present iodine changes from brown to blue/black.
  3. Put a drop of iodine in each spot. Every 10 seconds drop a sample of the mixture into a well on the spotting tile using a pipette. When the iodine solution remains brown record the total time taken.
  4. Repeat with the water bath at different temperatures to see how it affects the time taken for the starch to be broken down.
  5. Remember to control all of the variables each time.
4
Q

What else can you investigate regarding enzymes?

A

pH