viruses

Question 1

what are viruses?

Answer 1

small obligate intracellular parasites

Question 2

what 2 basic components make up a virus?

Answer 2

nucleic acid, protein

Question 3

what are the 2 nucleic acids?

Answer 3

DNA and RNA

Question 4

what are the 2 protein types?

Answer 4

structural proteins
non structural proteins

Question 5

what are structural proteins

Answer 5

proteins that make up the viral structure

Question 6

what are non structural protein

Answer 6

proteins (enzymes) needed for viral replication

Question 7

viruses are what?

Answer 7

inert outside the host cell

Question 8

what are virsues depended on?

Answer 8

fully depend on the biochemical machinery of the host cells

Question 9

what is the main purpose of a virus

Answer 9

the main purpose of a virus is to deliver its genome into the host cell

 and to use the host cell to replicate and synthesise viral proteins

Question 10

enveloped viruses?

Answer 10

envelop consists of a lipid
bilayer with proteins
embedded in it

is derived from the membranes of the host cell

Question 11

viral nucleic acid structure and example

Answer 11

DNA or RNA
Double stranded (ds)
Single stranded (ss)
Linear
Circular
Segmented
Single copy
Multiple copies

Question 12

where is the hereditary info of the virus encoded

Answer 12

RNA or DNA

Question 13

how is the hereditary info passed on

Answer 13

hereditary info is the virus is encoded in the RNA or DNA

it is passed on to new viruses through replication of the viral nucleic acid

which is followed by host synthesis of viral proteins

Viral Nucleic acid + Viral Protein = new virus particle

Question 14

what is viral nucleic acid used for?

Answer 14

replication

Question 15

what is viral protein used for?

Answer 15

transcription and translation

Question 16

alternate splicing

Answer 16

allows different proteins to be produced by the same gene

involves a complex series of cuts on the nuclear material followed by a “stitching” together

Question 17

what is the viral capsid?

Answer 17

The protein coat that envelopes viral genetic material is known as a capsid

Question 18

what is the capsids composed off?

Answer 18

protein subunits called capsomeres

Question 19

what does the viral capsid help?

Answer 19

• protect the viral genome from host nucleases
• attach the virion to specific receptors on the host cell during infection

Question 20

summarise capsid proteins

Answer 20

coded by the virus genome

capsids are formed as single or double protein shells

multiple protein copies need to self-assemble to form the continuous three-dimensional capsid structure

Question 21

what are the 2 basic self assembly patterns for a viral capsid?

Answer 21

helic symmetry
icosahedral symmetry

Question 22

what is a helical symmetry?

Answer 22

the
protein subunits and the
nucleic acid are arranged
in a helix

Question 23

what is a iscosahedral symmetry?

Answer 23

the protein subunits assemble into a symmetric shell that covers the nucleic acid-containing core

Question 24

whats the point of a viral envelope?

Answer 24

helps to protect the nucleocapsid

and helps it attach to the membranes of the host cells they infect

Question 25

what is part of the virus that is prone of mutation?

Answer 25

the capsid and the viral envelope

Question 26

what is a postive feature of the viral envelope

Answer 26

helps the virus stay undetected longer by a host’s immune
response

Question 27

how are non enveloped or naked viruses protected?

Answer 27

by their capsid alone

Question 28

summary of bacteriophage?

Answer 28

are specific to one or a limited number of bacteria

they are named after the bacteria group, strain, or species that they infect

Question 29

what is bacteiraphage head purpose?

Answer 29

made up of one or more proteins which coats and protects the nucleic acid

Question 30

what is the bacteriphage tail composed off?

Answer 30

a hollow tube through which the nucleic acid passes through when the bacteriophage infects a host cell

Question 31

what does the t4 phage have?

Answer 31

a tail with a base plate with tail fibers that aid the phage in attaching itself to a bacterial cell

Question 32

what can bacteriophages be useful for?

Answer 32

phage therapy

Phages are used therapeutically for the treatment of pathogenic bacterial infections that are resistant to antibiotics

Question 33

how can be bacterophages be used for diagnostic tools?

Answer 33

Bacteriophage is also used in identifying pathogenic bacteria ( phage typing) in diagnostic laboratories