Virology

Question 1

Viruses are found on few materials.

True or false?

Answer 1

False - they’re found on or in just about every material on Earth

Question 2

Viruses only infect mammals.

True or false?

Answer 2

False - they infect every form of life, even other viruses

Question 3

What is the nucleic acid in viruses?

Answer 3

Either DNA or RNA either single stranded or double stranded

Question 4

What is coating the virus?

Answer 4

Protein capsid coat - surrounds DNA or RNA to protect it

Could also have lipid membrane that surrounds the protein coat

Question 5

How can a virus cause cancer in humans?

Answer 5

Viruses aggravate tissues and cause constant inflammation (HPV, HBV, HCV) and chronic infection with a virus can cause cancer at a site of persistent infection

Question 6

What is meant by saying that viruses are obligate parasites?

Answer 6

They require an organisms for their propogation and are otherwise inert.

Question 7

What is the simplest definition of a virus?

Answer 7

A small bundle of information that reprograms a cell to make more of itself.

Question 8

What is the size range of viruses?

Answer 8

30nm to 300nm

Question 9

What factors are used to classify viruses?

Answer 9

Size

Nucleic acid

Coating

Question 10

What does protein do on a virus?

Answer 10

Coat the virus, aiding in entry and initiation of replication

Question 11

What are viruses made of?

Answer 11

Protein

Virus genome

Lipids (sometimes, lipid membrane coat from host cell)

Small cofactors (in some)

Question 12

Virion

Answer 12

Infectious particle oustide of cells composed of nucleic acid, protein capside and possibly an envelope. Can be extracellular or intracellular.

Question 13

Most viruses have proteins that _____ host cells and immunity

Answer 13

Alter

Question 14

Is the nucleic acid in viruses composed of a single fragment or multiple fragments?

Answer 14

It can be either - for example, influenza A virus’s genome has 8 RNA segments

Question 15

The more ______ the eukaryotic genome, the easier it is to design therapeutic interventions

Answer 15

Unlike

Question 16

Where do viruses bind on host cells for entry?

Answer 16

To receptors on the host cell’s surface. This allows either the whole virus to enter or allows the virus genome to enter.

Question 17

What are the 5 basic types of viral symmetry?

Answer 17

Question 18

Are naked viruses more or less stable than encapuslated viruses?

Answer 18

More stable in environment

Question 19

What are the DNA viruses?

Answer 19

Herpes

Hepadna

Adeno

Anello

Papova

Parvo

Pox

Question 20

Arboviruses are transmitted by _____

Answer 20

Arthropods (mosquitoes)

Question 21

Naked (No lipid envelope) viruses are transmitted via ________

Answer 21

Fecal oral route

Question 22

Enveloped viruses are sensitive to temperature and humidity changes.

True or false?

Answer 22

True

Question 23

What is tropism?

Answer 23

Entry occurs via virus-receptor interactions

Question 24

What is permissiveness?

Answer 24

Entry and replication of virus –> just because a virus enters the cell does not mean the internal cellular environment will allow for replication, need to differentiate between entry and entry + replication (permissiveness)

Question 25

Describe viral replication.

Answer 25

Question 26

The diseases caused by the virus is dependent on a virus's \_\_\_\_\_\_\_\_

Answer 26

Tropism

Question 27

What are viral epitopes?

Answer 27

Antigens on the surface of the virus that differ between strains or variants that are recognized by our antibodies

Question 28

What are the different serological methods for detecting viruses?

Answer 28

Neutralization - patient antibodies bind to antigen to neutralize antigen Antigen capture - put antidbody for antigen on plate, run serum over plate, design antibody with probe that binds to antigen (measures amount of antigen in patient) Indirect ELISA - put antigen on plate, run patient serum over plate, antibodies will bind to antigen, design probe antibody for patient antibody to detect levels of patient antibody Detect patient antibodies directly - put antibody for patient's antibody on plate, run serum over plate, design antibody with probe for patient's antibody --\> detect levels of antibody

Question 29

Why are there so few antiviral drugs?

Answer 29

Because viruses use an organisms enzymes to replicate so you can't target the host's enzymes or there will be terrible side effects. As such, most antivirals target virus specific proteins.

Question 30

What is a modified live vaccine?

Answer 30

One where a small amount of the virus is allowed to replicate in the host and produces mild clinical signs. They contain live organisms and may cause disease in stressed hosts or if given via the wrong route.

Question 31

What is a killed inactivated vaccine?

Answer 31

Either the whole pathogen or just part of it that is totally inactive

Question 32

What are some examples of novel vaccines?

Answer 32

Recombinant protein vaccines (make protein from virus, only produces humoral response, high cost) Subunit vaccines Toxoid vaccines Conjugate vaccines

Question 33

Describe the process of action of a live attenuated virus.

Answer 33

Question 34

What are some examples of viruses with dsDNA? With ssDNA? With dsRNA? With ssRNA?

Answer 34

HPV, EBV, HSV Polio, common cold Rotavirus Influenza, measles, ebola