2019

Question 1

Role of antibodies on producing a positive Elisa test

Answer 1

1. Antibody binds to complementary antigen
2. Antibody with enzyme attached is added
3. Antibody attaches to antigen
4. Substrate is added which reacts with the enzyme producing a colour change

Question 2

Explain why it is more useful to use index of diversity than to record species richness

Answer 2

1. Index of diversity measures pop size of each species

2. So useful bc it may be many of some species

Question 3

Suggest how the scienctist measured rate of water flow

Answer 3

Time to fill a container of knowing volume

Question 4

There properties of solutions

Answer 4

Isotonic: to prevent bursting of cell
Buffer: to prevent denaturing of enzymes
Ice cold: reduce enzyme activity

Question 5

Explain how AS of an enzyme cause a high rate of reaction

Answer 5

1. Lowers activation energy
2. Induced fit causes AS to change shape
3. So ES complexes cause bonds to form

Question 6

Explain wha the positions of the spots in the diagram show about these AAs

Answer 6

1. Move to -ve electrode bc they’re +vely charged
2. Spots move at different rates bc AAs have different mass
3. One spot has 2 AA bc same mass

Question 7

Why ABZ still used despite affect on healthy cells

Answer 7

Cancerous cells divide uncontrollably

Question 8

Conclude affect of ABZ on tumour cells

Answer 8

1. ABZ increases cyclin B
2. So mitosis starts but doesn’t end
3. ABZ lowers ratio of Bcl to Bax
4. So apoptosis occurs

Question 9

Evaluate use of ABZ

Answer 9

For

• it could be used bc it prevents the spread of tumour cells early on by stopping mitosis

AGAINST

• causes damage to healthy cells = severe side effects
• effectiveness unknown