Viruses, Retroviruses, and Viral Diseases

Flashcards about Viruses, Retroviruses, and HPV based on lecture notes.

What is the main topic of today's lecture?

Reviewing information about viruses, retroviruses, and other viral diseases.

What topics will be covered on the upcoming lecture exam?

Microbial genetics, pathogenicity, viruses, epidemiology, central dogma practice problems, eukaryotes, prokaryotes, and viruses.

What enzyme is specific to retroviruses?

Reverse transcriptase

How are viruses defined?

Obligatory intracellular parasites that reproduce inside a host cell, stealing resources such as ATP and building blocks.

Where does DNA replication occur in a host cell?

The nucleus because that's where DNA polymerase is.

Where does Protein production happen in a host cell?

The cytoplasm because that's where the ribosome is.

What are the general steps of viral infection and replication?

Attachment, viral entry/uncoating, replication of the genome, protein production, assembly, and release.

What's the first step in viral infection?

Adhesion on the virus attaching to a receptor on the host cell.

What enzyme is needed to replicate single-stranded viral DNA?

DNA polymerase

What enzyme do viruses use to produce RNA from DNA?

RNA polymerase

What enzyme do viruses use to produce proteins?

The ribosome

What forms do RNA viruses come in?

Single-stranded, either sense or antisense, or double-stranded.

How do retroviruses differ from other RNA viruses?

They use RNA as a template to produce DNA with the help of reverse transcriptase.

What is reverse transcriptase?

Viral enzyme that uses RNA as a template to produce DNA and introduces lots of mutations.

Give some examples of retroviruses?

HIV and hepatitis B

What happens when a retrovirus infects a cell?

An adhesion binds to a receptor on the host cell, causing viral entry and the release of the viral genome.

What enzyme inserts the viral DNA into the host DNA?

Viral integrase

What is a provirus?

A cell with viral DNA integrated into its chromosome.

Describe the latent stage

The cell can be infected but not be making new viral particles until there is some outside event that triggers it.

What happens during the induction event in viral replication?

When the virus becomes activated, starts to use the DNA genome to make RNA copies and viral proteins, and assembles new viruses that will then leave the cell.

How do viruses exit host cells?

Non-enveloped viruses rupture the cell, while enveloped viruses bud off, taking some of the host cell membrane with them.

What is the mode of transmission for SARS CoV-2 (COVID-19)?

Vehicle transmission (airborne transmission)

What protein serves as the receptor for SARS-CoV-2 on host cells?

ACE2

What are the three main components of the immune response against SARS-CoV-2?

Neutralizing antibodies, cytotoxic T cells, level of the immune response

How HIV affects the immune system

Helper T cells are very important part of an immune response.

Compare single-stranded RNA viruses with stem strand with retroviruses

Single-stranded RNA viruses use their genome to make messenger RNA, but retroviruses do not.

How does reverse transcriptase use its genome

They produce DNA instead and integrates into Host genome

What causes random mutations in SARS CoV two

Those random mutations are caused by RBRP and the immune system

Treatment of regeneron Remdesivir ACE two

Used or are used to treat COVID-19

What is HPV?

A double-stranded DNA virus, non-enveloped, that enters through the skin and can cause papillomas (warts).

What specific country has a HPV vaccine?

Australia