Enzymes topic questions

Question 1

Devise a plan to investiage the ph on the activity of its enzyme(3)

Answer 1

add enzyme soultion plant cell (1)

Test for presence of starch(1)
test each minute at set time intervals(1)
Repeat at more than one pH(1)
make sure the volume of concentarion of the amalyse stays the same(1)

Question 2

Describe how starch is broken down into glucose(2)

Answer 2

amylase(1)
starch fits into active site(1)

Question 3

Name the enzyme that breaks down starch(1)

Answer 3

Amalyse(1)

Question 4

Describe a test to identify fat(2)

Answer 4

Mix the food in ethanol and pour into water(1)
white emulsion forms(1)

Question 5

Describe a chemical test for startch(2)

Answer 5

add iodine soulution(1)
iodine soultion changes from brown to blue black(1)

Question 6

Explain why the calorimeter has a lid(2)

Answer 6

it is an insulator reduces the heat loss(1)
so energy from sugar is used to heat water(1)

Question 7

Describe the condintions in the stomach that allows pepsin to work effectively(2)

Answer 7

pH has to be two(1)
the stomach secrets hydrocholric acid(1)

Question 8

Devise a method to compare the energy content of two foods using this equipment(6)

Answer 8

Using the equipment
add water to the boiling tube(1)
place food on mounted needle
take the starting temp of the water
ignite burn the food

Controlling variables
mass of food measured with a balance
volume of water with a measuring cylinder