L06-Nature and properties of micro organisms

Question 1

What are prions?

Answer 1

Infectious particles which are smaller than viruses. They contain no nucleic acids (DNA or RNA)

Question 2

What sort of diseases do prions cause and what is the mechanism behind this?

Answer 2

They caus progressive fatal neurodegenerative contitions. This is due to misfolded prion proteins being incorporated into brain tissue.

Question 3

What kind of effect do prions have on the brain tissue itself?

Answer 3

Cause spongiform encephalopathies, this leaves large lesions or vacuoles in the brain

Question 4

What are viruses?

Answer 4

Obligate intracellular parasites

meaning they are restricted to being in cells to reproduce

Question 5

What is the structure of a virus?

Answer 5

Genetic material (DNA or RNA) contained within a shell called a capsid.

Question 6

Are bacteria eukaryotes or prokaryotes?

Answer 6

They are prokaryotes as they lack membrane bound organelles.

Question 7

What is the difference between a gram negative and a gram positive bacteria?

Answer 7

Gram negative species have a thin peptidoglycan cell wall sandwiched between two membranes whereas the gram positive species have a thick peptidoglycan wall outside their membrane

Question 8

Are fungi eukaryotic or prokaryotic?

Answer 8

Eukaryotic as they contain membrane bound organelles.

Question 9

What is usually the case if an individual suffers from a systemic fungal infection?

Answer 9

They are immunosupressed.