HIV

Question 1

HIV Def and what it needs…

Answer 1

An individual virus that require energy, resources and machinery of the host cell.

Question 2

Name the five parts of HIV virus

Answer 2

Envelope, HIV enzyme, RNA genomes, HIV envelope proteins, capsid

Question 3

Describe the life cycle of HIV virion

Answer 3

Attachment, uncoating, reverse transcription, integration, transcription of HIV DNA, Translation of HIV mRNAs, new virion ensemble, exit

Question 4

Describe the attachment and entry process

Answer 4

Virus interact with receptor protein in the membrane of host cell (spec cells as tackles have this)
HIV only infects certain immune system cells ex T cells that have the membrane protein needed for virus to attach.

Question 5

What is the name of the membrane protein that all infected cells have?

Answer 5

CD4

Question 6

Describe reverse transcription and function

Answer 6

Using RNA template to form DNA strand
Reverse transcriptase only present in HIV virion (no host cell has this enzyme)
Reverse transcription is inaccurate which increases chance of mutations of virus.

Question 7

Describe the process of integration

Answer 7

Integrate: Inserts double stranded HIV DNA into one of the host cells chromosomes.
Integration of HIV DNA genome allows expression of HIV genes in host cells and is passed on when cell divides which explains why HIV is incurable= it is a part of the DNA of the cells after insertion happens
Membrane surrounding cell comes from host cell

Question 8

Why is HIV able to replicate so fast?

Answer 8

Because of reverse transcription, it is not very accurate and mutations are created easily
Mutations allow the virus to become drug resistant

Question 9

Describe the function of AZT

Answer 9

It inhibits copying of HIV genome when.
Only stops NEW adding.
OH needed to add new nucleotide, AZT prevents that.

Question 10

What can remove AZT from growing DNA?

Answer 10

Mutations

Question 11

What mechanisms can alter frequency of an AZT resistance mutation prior to treatment?

Answer 11

Genetic drift
Gene flow
Mutations
Natural selection, will most likely increase frequency

Question 12

Resistance to multiple drugs…

Answer 12

Require multiple mutations

Question 13

Why is it more effective to use more than one treatment?

Answer 13

Because resistance to multiple drugs require multiple mutations