Biological knowledge in response for disease

Question 1

Anti-viral drugs work in different ways. Explain two modes of action that are used in anti-viral drugs.

Answer 1

1. Preventing DNA synthesis in the host cell: This mode will stop viruses from being reproduced.
2. Inhibiting the enzymes involved with the release of the viruses from the host cell: This mode will stop viruses spreading to infect other cells.

Question 2

Outline a possible reason why chemical 4 from a rational drug design could be more successful.

Answer 2

• Fewer adverse side effects of this drug
• Provides an extra binding site for, for example, another drug or enzyme
• The drug passes more readily into cancer cells

Question 3

How does the drug Relenza work? (antiviral drug)

Answer 3

Relenza works by inhibiting the enzymes that release viruses from host cells.

Question 4

Explain why antibiotics are a useful treatment for bacterial diseases but ineffective against viral diseases.

Answer 4

• antibiotics inhibit the reproduction of bacteria/cell wall synthesis/protein synthesis
• but viruses do not have cellular structures as they are not cellular
• viruses are reproduced by a host cell.

Question 5

How do antibiotics work?

Answer 5

reproduction/binary fission
cell wall synthesis
protein synthesis.

Question 6

With reference to genetic material, what is the difference between retrovirus and an adenovirus?

Answer 6

A retrovirus is a virus that has RNA as its genetic material, whereas an adenovirus has DNA as its genetic material.

Question 7

Pandemics are often caused by viruses. The reason that pandemics are often caused by viruses rather than other pathogens is that viruses

Answer 7

They mutate into new strains to which humans have no immunity.
The reason that pandemics are often caused by viruses rather than other pathogens is that viruses mutate into new strains to which humans have no immunity.

Question 8

What is meant by the term ‘epidemic’?

Answer 8

When a disease spreads through a population in a small geographical area.

Question 9

Why might an antiviral drug not be effective in a years time?

Answer 9

It is possible that the virus has mutated to a new strain.

Question 10

What would make a rationally designed drug the most effective?

Answer 10

Chemical has a shape which will combine exactly with the active site.

Question 11

What is a vector?

Answer 11

An organism that carries a pathogen from one host to another.

Question 12

What vector is used in gene technology?

Answer 12

Plasmid.

Question 13

What property is not necessary for a vector to have?

Answer 13

.