Topic 2: Viruses

Question 1

What form will genetic information be in in Viruses?

Answer 1

DNA or RNA

Question 2

What protects the genetic material in viruses?

Answer 2

A protein coat called a capsid
Capsid is made up of repeating sub units called cap somieres

Question 3

What is found on the outside of a virus?

Answer 3

Glycoproteins/attachment spikes

Question 4

Wat is he purpose of attachment proteins?

Answer 4

Other than attachment they can act as antigens
So the virus is identified by the hosts immune system

Question 5

What is the size of a virus?

Answer 5

Smaller than a bacterial cell

Question 6

How does the structure of a bacterium differ to a virus?

Answer 6

Bacteria have:
Ribosome,cell wall, cell membranes, plasmids, flagella,capsule
Viruses do not

Question 7

How do viruses replicate?

Answer 7

They attach to the host cell surface using attachment proteins
The attachment proteins bind to complementary receptor proteins in the cell surface membrane of host cells
The relationship between the virus attachment protein and the receptor protein is specific
The virus penetrates the cell membrane and injects its nucleic acid
Uses host cell machinery to replicate viral rna or dna
New viral proteins are made by ribosomes
Host cell destroyed when new virus leaves