Microorganism And Disease

Question 1

What are pathogens?

Answer 1

Pathogens are invading microorganisms

Question 2

What are the 5 groups of pathogens

Answer 2

Viruses 
Bacteria
Fungi
Metazoa
Protoctista

Question 3

What are viruses?

Answer 3

Arrangements of genetic material and protein that invade other living cells and take over their biochemistry to make more viruses

Question 4

What is the capsid and what it is made out of?

Answer 4

It is the protein coat. It is made up of many repeating protein units known as capsomeres arranged in different ways

Question 5

Why is good having a capsid?

Answer 5

The repeating protein units minimize the amount of genetic material needed to code for the coat production

Question 6

Why are the good and bad points of a virus having a lipid envelope?

Answer 6

It makes it easier for it to pass from cell to cell

BUT

It makes them vulnerable to substances that can dissolve the lipid membrane. Eg. Ether

Question 7

What are the 5 structural things viruses have?

Answer 7

Capsid
Nucleic acids
VAPs (receptors)
Capsomere
Envelope

Question 8

What does the viral DNA do?

Answer 8

Acts as a template for both new viral DNA and mRNA needed to induce synthesis if viral proteins

Question 9

What are some examples of viruses with DNA?

Answer 9

Smallpox
Adenoviruses
Bacteriophages

Question 10

What does viral RNA do?

Answer 10

It directs the synthesis of reverse transcriptase which makes DNA molecules corresponding to the viral genome. This DNA is then used as a template.

Question 11

What are some examples of viruses with RNA?

Answer 11

Tobacco mosaic virus

HIV

Question 12

How do virus attach to their hosts?

Answer 12

Through antigens (VAPs) which target proteins in the host cell surface membrane.

Question 13

Where do viruses reproduce?

Answer 13

Within body cells

Question 14

What happens after bacteriophages insert their DNA in the host cell?

Answer 14

The viral DNA forms a circle (PLASMID) within the bacterium

Question 15

How can viruses infect cells?

Answer 15

By endocytosis: the host ingests the capsid releasing viral genetic material.

Or

By vectors like animals

Question 16

What are the 2 routes of infection?

Answer 16

Lysogenic and lytic pathway

Question 17

What is the lysogenic pathway?

Answer 17

When the virus inserts its provirus (DNA) in the host. It replicates every time the host cell divides.

The virus is dormant. mRNA is not produced because one viral gene causes the production of a repressor protein, so the rest of the viral genetic material isn’t translated

Question 18

What is the lytic pathway?

Answer 18

After viral DNA is replicated, mature viruses are made and eventually the host cells release viruses.

Question 19

How do retroviruses infect cells?

Answer 19

It attacks the cell
The viral RNA enters the host cell
The viral RNA is translated into viral DNA by reverse transcriptase in the cytoplasm because the RNA cant be used as mRNA
The viral DNA is incorporated into the host DNA in the nucleus and it directs the production of new viral RNA, mRNA and coat proteins
The new viral particles are assembled and leave the host cell by exocytosis. Viral DNA remains in the nucleus so this process is repeated

Question 20

How to viruses causes symptoms?

Answer 20

By the lysis of the host cells by making them release their own lysosomes and digest themselves from the inside.

Or by making toxins that inhibit cell metabolism