PAG - Investigation into the effect of substrate concentration on enzyme activity

Question 1

What does the substrate concentration affect

Answer 1

how much product is made

Question 2

Catalase

Answer 2

Increases the breakdown of hydrogen peroxide

Question 3

Hydrogen peroxide

Answer 3

toxin produced as a by-product of reactions in cells

Question 4

where is catalase found in high concentrations

Answer 4

raw potatoes

Question 5

Step 1 - preparation

Answer 5

• grind 2cm3 piece of potato cylinder with 5cm3 distilled water to make a smooth paste containing the enzyme
• place 10cm3 hydrogen peroxide into a test tube

Question 6

what happens after we have prepared for the experiment

Answer 6

• using forceps dip a filter paper disc into enzyme suspension, tapping off excess
• drop filter paper disc into hydrogen peroxide solution, and measure time taken from hitting surface to float up again

Question 7

Health and safety -

Answer 7

• Hydrogen peroxide = corrosive = take care
• Glasswear = may smash = handle with care
• Bags/Chairs = tripping hazard = put away

Question 8

Independent variable

Answer 8

concentration of hydrogen peroxide - %

Question 9

Dependent variable

Answer 9

time taken for discs to resurface - secs

Question 10

Control variables

Answer 10

• size of discs
• make sure potatoes are cut to the same size before crushing
• volume of solution
• volume of water mixed with hydrogen raw potato

Question 11

percentage error calculation -

Answer 11

uncertainty value / your measurement x100