The Immune System

Question 1

Describe how HIV is replicated.

Answer 1

Attachment proteins attach to receptors on helper T cell/lymphocyte;
2. Nucleic acid/RNA enters cell;
3. Reverse transcriptase converts RNA to DNA;
4. Viral protein/capsid/enzymes produced;
5. Virus (particles) assembled and released (from cell);

Question 2

what surrounds the RNA/DNA and reverse transcriptase enzymes?

Answer 2

capsid

Question 3

Some of the antigens found on the surface of tumour cells are also found
on the surface of healthy human cells.
Use this information to explain why treatment with an ADC often causes
side effects.

Answer 3

-bind to health cells
- cause cell death

Question 4

Describe how the human immunodeficiency virus (HIV) is replicated once
inside helper T cells (TH cells).

Answer 4

RNA converted into DNA using reverse transcriptase;
DNA enters nucleus via nuclear pore
Viral DNA transcribed to form mRNA
mRNA is translated to form viral proteins

Question 5

drugs vs transplant

Answer 5

-drugs you need to take daily
-may take long time to find matching Donner

Question 6

Suggest and explain how the viruses became able to infect other species
of frog.

Answer 6

mutation in DNA changes tertiary structure of attachment protein so complimentary to other species receptors

Question 7

Determining the genome of the viruses could allow scientists to develop a
vaccine.

Answer 7

identify proteome to identify potential antigens

Question 8

What is a monoclonal antibody?

Answer 8

(Antibodies with the) same tertiary structure

Question 9

explain Eliza testing

Answer 9

(First) antibody binds/attaches /complementary (in shape) to antigen;
2. (Second) antibody with enzyme attached is added;
3. (Second) antibody attaches to antigen;

Accept (second) antibody attaches to (first) antibody
(indirect ELISA test).

4. (Substrate/solution added) and colour changes;
   Only award if enzyme mentioned.

Question 10

Describe and explain the role of antibodies in stimulating phagocytosis.

Answer 10

mark antigens and cause them to clump together (agglutination)

Question 11

During vaccination, each animal is initially injected with a small volume of
venom. Two weeks later, it is injected with a larger volume of venom.
Use your knowledge of the humoral immune response to explain this
vaccination programme.

Answer 11

B cells specific to the venom reproduce by mitosis;
(B cells produce) plasma cells and memory cells;
The second dose produces antibodies (in secondary immune
response) in higher concentration and quickly

Question 12

What is an antigen?

Answer 12

Foreign protein;
2. (that) stimulates an immune response / production of antibody;

Question 13

What is an antibody?

Answer 13

a pretien with a specific tertiary cell peoduced by B cells