Viruses

Question 1

Do viruses share characteristics with cells?

Answer 1

No

Question 2

What is the virion and what does it contain?

Answer 2

Infectious viral particle
Nucleic acid surrounded by protein coat
Capsid

Question 3

What is the protein coat for?

Answer 3

A protection and transmisttion

Question 4

What is nucleic acid?

Answer 4

DNA or RNA never both

Question 5

What is the capsule made of?

Answer 5

Capsomere submits
One or several types of proteins

Question 6

What does the envelope contain?

Answer 6

Lipids
Proteins
Carbohydrates

Question 7

What is the envelope?

Answer 7

A lipis bilayer that surrounds the viral capsid

Question 8

Are all viruses enveloped?

Answer 8

No

Question 9

How are viral genomes classified?

Answer 9

Nucleic type
Strategy for replication
Morphology

Question 10

Can viral gemones be RNA or DNA?

Answer 10

Both

Question 11

Do Viral genomes have to be singles stranded or double stranded?

Answer 11

Both

Question 12

What are the different types of viruses?

Answer 12

HIV
Hepatitis B
Ebola virus
Advenovirus
Influenza
Bacteriophage

Question 13

What is the basis of host range?

Answer 13

The ability to hind to the host cell

Question 14

What is the attachment called whith the interaction between ligands on the virus surface and the receptors on the cell surface?

Answer 14

Lock and key

Question 15

What is the lytic viral infection cycle?

Answer 15

Attachment
penetartion
Uncoating
Replication
Assembly
Viron release

Question 16

What is it meant by attachment in the lytic viral infection cycle?

Answer 16

Proteins on the capsid or envelope interact specifically with receptors on the host cell surface

Question 17

What is it meant by penetration in the lytic viral infection cycle?

Answer 17

Attachment induces conformational changes in the virus resulting in fusion of membranes
Some viruses can also enter ny endocytosis

Question 18

What is it meant by uncoating in the lytic viral infection cycle?

Answer 18

Viral capsid is removed and degraded by viral or host enzymes
Viral DNA is released

Question 19

What is it meant by replication in the lytic viral infection cycle?

Answer 19

Transcription and translation of the viral genome is initiated
New viral genomes and viral proteins are made

Question 20

What is it meant by assembly in the lytic viral infection cycle?

Answer 20

Viral proteins are packaged with the newly synthesised ciral genome into virons ready to be released from the host cell

Question 21

What is it meant by viron release in the lytic viral infection cycle?

Answer 21

LYSIS or BUDDING
Lysis results in death of the cell and the viruses are cytolytic
Budding results in the acquisition of a viral envelope, do not kill the cell and are known as cytopathic

Question 22

What are the differences between lytic and lysogenic cycles of bacteriophage?

Answer 22

Lysic results in lysis of the host cell and lysogenic do not lyse

In lytic the viral DNA is not intergrated into the host genome whereas in lysogenic the viral DNA is integrated into the host genome and the prophage stage is when viral genome is part of the host genome

Lytic, the viral DNA replication is seperate from host DNA replication and in lysogenic the viral DNA is replicated along with normal host DNA replication

Lytic progeny virus is released during lysis or budding and in lysogenic the progeny virus is not released until switched back to lytic cycle

Example of lysic is influenza that effects the lungs
Example of lysogenic is herpes virus that can be undetected for a long period of time