Micro Ch 13

Front 1

Define Viruses

Back 1

1. tiny (nm)

2. acellular

3. infectious agents

4. Has DNA and RNA

5. Has no cytoplasmic membrane

6. No cytosol, no organelle

7. No replication on it own and no metabolic

activity

Front 2

Define Virion

Back 2

1. It consist of protein coat called Capsid.

2. Some has a envelope called Phospolipid

membrane.

Front 3

What does the envelope do for the Virion

Back 3

It protect and attached to the host.

Front 4

The capsid is surrounded by what?

Back 4

Nucleic acid

Front 5

The nucleic acid and capsid together is called?

Back 5

nucleocapsid

Front 6

Capsids has a subunit called?

Back 6

capsomeres

Front 7

What is the size of viruses?

Back 7

The smallest about 24nm and the largest is about 500nm

Front 8

What are the shapes of viruses?

Back 8

1. Helical- has a spiral shape

2. Polyhedral-has a spherical (the most common)

3. Complex- has many shapes

Front 9

Viruses are classified by what name?

Back 9

Family name

Front 10

What is the stages of lytic replication(5)?

Back 10

1. attachment

2. entry

3. synthesis

4. assembly

5. release

Front 11

The naked viruses enter the host by_____.

Back 11

direct penetration

Front 12

Define dsDNA

Back 12

1. It a double stranded DNA

2. dsDNA uses a strand of DNA as a template

3. after RNA is transcribed from viral DNA in the nucleus and capsomere protein is made in the

cytoplasm.

4. Then the capsomeres enter the nucleus where new virions is made.

Front 13

Give an example of the dsDNA viruse.

Back 13

1. Poxvirus

2. Hepatitis B

Front 14

Define ssDNA viruses

Back 14

1. It a single strand DNA (parovirus)

2. Cell can not use ssDNA, so when the parovirus enter the nucleus it produce a new strand of DNA.

3. It form dsDNA and mRNA replicate the new ssDNA

Front 15

What are the four RNA viruses?

Back 15

1. Positive-sense, single stranded RNA

(designated +ssRNA)

2.retroviruses (a kind of +ssRNA virus )

3. negative-sense single strande RNA (-ssRNA)

4. double stranded RNA (dsRNA)

Front 16

Define positive ssRNA

Back 16

It a single-stranded viral RNA that can act directly as mRNA. It complement the negative strand RNA and is transcribed from +ssRNA. -RNA serves as a template for transcription. No cell transcribe RNA to RNA.

Front 17

Define Retroviruses

Back 17

It do not use their genome as mRNA, it used +RNA by reverse transcriptase carried within the capsid. The DNA intermediary serves as a template for synthesis of additional +RNA molecule, which act both as mRNA for protein synthesis and as a genomes for new virions

Front 18

Give an example of an retroviruse.

Back 18

HIV

Front 19

Define negative ssRNA viruses?

Back 19

It a single stranded RNA. It can be use to

synthesize protein. It must use mRNA(+).

-RNA is not recognized by ribosome. It depend on +RNA to serve as a template to make -RNA.

Front 20

Name diseases caused by -ssRNA.

Back 20

1. rabies

2. flu

Front 21

Define dsRNA

Back 21

This is a double stranded RNA and it mRNA is used as a template to produce more dsRNA.

Front 22

dsRNA viruses causes what is infant in most cases?

Back 22

Diarrhea

Front 23

Define budding

Back 23

1. It pushed through host membrane

2. picks up part of the host membrane to become a viral envelope.

3. The virus is slowly released.

4. The host is not quickly lysed

5. It is persistent in infection

Front 24

Define Latency

Back 24

Some viruses remain dormant an example is chick pox and herpes.

Front 25

Latency is also called _______or ______

Back 25

latent viruses or proviruses

Front 26

True of False HIV is more like lysogenic phage?

Back 26

true

Front 27

True or False the provirus is reversible.

Back 27

False