Flashcards
HIV
Flashcards do conjunto (55)
- 1Give the 9 stages of the HIV lifecycle?Entry
Fusion
Uncoating
Reverse transcription
integration
replication/ translation
assembly
budding
maturation - 2Is HIV an enveloped or a naked virus?Enveloped
- 3What is HIV's baltimore classification?Group VI
- 4What type of cell does HIV mainly infect?CD 4+ T cells
- 5Give 5 other cells HIV can infect, but does not lyse these cell types?Natural killer cells
CD 8 + Killer T cells
macrophages
dendritic cells
cells of the nervous system - 6What is the genomic makeup of HIV?2 single strands of + RNA
- 7What 2 proteins make up HIV's envelope?gp120 and gp41
- 8gp120 is?glycoprotein
- 9gp41 is a?transmembrane protein
- 10HIV's capsid is made from what protein?p24
- 11GP120 is involved in?Cell attachment and uptake
- 12GP41 is involved in?cell attachment and cell fusion
- 13The cytoplasmic tail of gp41 interacts with the...HIV-1 matrix protein p17
- 14How many different reading frames does the HIV virus have?3
- 15Give a definition of polyproteinslarge proteins which are broken down into smaller proteins via the protease enzyme leading to smaller functional proteins. They only need one regulatory system in order to encode for 7 different proteins, instead of encoding for each protein separately. Polyproteins are space saving
- 16What is the purpose of the HIV virus having 3 reading frames?Allows the virus to encode for more proteins from less nucleotides
- 17HIV has 3 genes encoding polyproteins what are they called?GAG
POL
ENV - 18What does GAG encode for?capsid and matrix
- 19What does POL encode for?Reverse transcriptase and integrase
- 20What does ENV encode for?GP120 AND GP41
- 21What is the name of the gene which HIV uses for the capsid?p24
- 22What 3 shapes if p24 arranged into?hexamers, dimers and pentamers
- 23What are co-receptors?chemokines
- 24What is the name of the HIV co-receptor found on macrophages?CCR5
- 25What is the name of the HIV co-receptor found on lymphocytes?CXCR4
- 26The rapid progression of HIV to AIDS is associated with what?A switch in co-receptor preference, early infection, HIV infects macrophages, during later infection, its preference changes to T-cell tropic or X4 subtypes
- 27During HIV attachment, gp120 binds to.....on host cell?CD4
- 28What is enfuvirtide?a fusion inhibitor, inhibits the fusion process and prevents the virus from infecting the cell. Prevents gp41 insertion into the membrane
- 29Give 3 examples of entry inhibitors?Enfuvirtide
Ibalizumab
maraviroc - 30Explain why some people have a natural resistance to HIV?They have mutations in the co-receptors which means that the virus can interact with CD4 but cannot enter the cell because they lack the co-receptor
- 31What happens in the reverse transcription complex?reverse transcription
- 32What happens in the pre-integration complex?contains the double stranded cDNA, which will be integrated into the host cell chromosome
- 33Where does integration occur?In the nucleus
- 34What happens during reverse transcription?takes viral RNA and converts it into ssDNA then into double stranded DNA.
- 35What are the 3 rules of reverse transcriptase?RT can only start from double stranded DNA nucleic acid and add nucleotides in the 5 prime to 3 prime directon
RT has polymerase and Ribonuclease H activity
Ribonuclease H will delete RNA in RNA/DNA duplex - 36What are he 3 biochemical activities of reverse transcriptase?RNA dependent DNA polymerase activity
Ribonuclease H
DNA dependent DNA polymerase activity - 37Give 2 examples of reverse transcriptase inhibitors?Zidovudine
AZT - 38Reverse transcriptase inhibitors are either?NNTI's or NNRTI's
- 39what is meant by nuclear import?Double stranded DNA of the virus enters the nucleus of the cell
- 40What is meant by integration?The viral genome is inserted into the host chromosome, viral DNA needs to be incorporated into host DNA
- 41What is the role of integrase during integration?cuts the hosts DNA, integrates and religate.
- 42is the site of integration random?No HIV is inserted into regions which are actively transcribed
- 43Give the name of an integrase inhibitor?Raltegravir
- 44How does raltegravir work?Targets the integrase viral DNA complex in the pre-integration complex, blocks integration of HIV therefore inhibit viral replication
- 45What areas do integrase inhibitors look for?Areas of high gene density, its target is not random
- 46What does the gag protein stand for?Group specific antigen
- 47The gag polyprotein has how many cleavage sites?5
- 48What happens during maturation?The polyprotein is inserted into the cell membrane and cleaved at 5 sites
- 49Cleavage of GAG protein by HIV Protease leads to the release of...MA- matrix protein
CA- Capsid protein
NC- Nucleocapsid
P6- plays a role in budding
SP1/SP2- spacer peptides - 50Polyproteins are cleaved by what?HIV protease
- 51If HIV protease does not cleave the polyprotein then what happens?Means that the viral particles have not undergone full maturation and are therefore not infective
- 52Give an example of a protease inhibitor?Saquinavir
- 53What is HIV-1 protease?99 amino acid homodimeric aspartyl protease
- 54How does saquinavir work?remains in the active site of HIV protease, so blocks its use and prevents maturation and cleavage, so viral particles cannot mature
- 55—
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- VPI FlashCards sobre HIV, criado por Samantha Gable em 03-09-2018.
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- Samantha Gable
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