Vriuses

Question 1

What are viruses

Answer 1

they are arrangemetns of gentic material and protein that invade other living cells and take over their biochemistry to make more viruses `

Question 2

What is the protein coat (capsid) made up

Answer 2

repeating protein units known as capsomers arranged in diffrent ways

Question 3

What is + for the presences of the lipid envlope

Answer 3

makes it easier for the viruses to pass from cell to cell

Question 4

What makes the lipid envlope vunerable

Answer 4

substances such as ether which dissolve the lipid membrane

Question 5

What is the benefit for using repeating units

Answer 5

It reduces the genetic materiel needed to code fro coat production

Question 6

What are VAPS (Virus attachment particles)

Answer 6

specfic proteins that target proteins in the host cell surface membrane

Question 7

How can viruses be classifed

Answer 7

genome and there mode of replication

Question 8

Viral gentic materail can be what

Answer 8

DNA or RNA and the nucleic acid is sometimes double stranded and sometimes single

Question 9

What is a DNA virus

Answer 9

contains DNA which can directly act as template for mRNA transcription and DNA replication

Question 10

What is a RNA viruses

Answer 10

Contain RNA and make new RNA from it : no DNA is made

Question 11

What is a retroviruses

Answer 11

type of RNA that directs the synthesis of the enzyme reverse trnascriptase This makes the DNA versions of the RNA genome
The DNA is incoprated into the host cell and used to make more viral proteins and RNA genome

Question 12

What is reverse transcriptase

Answer 12

an enzyme synthesised in the life cycle of a retrovirus that makes DNA molecules corresponding to the vrial RNA genome

Question 13

Explain latency

Answer 13

Talk about it

Question 14

What is lysogney

Answer 14

the period when a virus is part of the reproducing host cell but does not affect it adversley

Question 15

What does latent mean

Answer 15

the state of non viruent virus within the host cell

Question 16

How are viruses classified

Answer 16

according to their strucuture and type of nucleic acid

Question 17

Features of an RNA and retrovirsues

Answer 17

Single strand of RNA

Reverse transcriptase enzyme produces cDNA from RNA template

Double stranded viral DNA intergrates into a host cells genome

Question 18

Describe the lytic pathway 1/2

Answer 18

`Virulent viruses inject nucleic acid into the host cells cytoplasm. Viral genetic info replicates immediately, independent of the host cell

Question 19

Describe the lytic pathway 2/2

Answer 19

many virons assemble , causing cell lysis

Question 20

What is a + ssRNA virus

Answer 20

viruses that contain a single strand of RNA that is a sense strand. It is used directly as mRNA for translation into proteins at the ribosomes

Question 21

what is the sense strand in +ssRNA used for

Answer 21

used directly as mRNA for translation

Question 22

What is - ssRNA virus

Answer 22

single strand of RNA in this virus is an anti sense strand

Question 23

Is tobacco mv ++ssrna or -

Answer 23

+ssrna which means it can be directly translated into proteins at the ribosomes

Question 24

is ebola –ssrna or +ssrna

Answer 24

• needs to be transcribed to produce mrna beforre translation