Pathogens

Question 1

define: pathogen

Answer 1

any biological agent that causes disease in a host.

Question 2

pathogens are a source of…

Answer 2

non self antigens

Question 3

examples of cellular pathogens?

Answer 3

bacteria, fungi, protistis, parasitic helminth worms

Question 4

examples of non cellular pathogens?

Answer 4

DNA/RNA viruses, prions.

Question 5

difference between infection and disease?

Answer 5

infection is when pathogens first enter the body and multiply; and this leads to disease – damage to body, and symptoms are present.

Question 6

define: virus

Answer 6

non-cellular agents consisting of genetic material that can replicate only within host cells (obligate intracellular parasites)

Question 7

living aspects of viruses?

Answer 7

they have genetic material (DNA or RNA) that encodes proteins and are self replicating inside of cells

Question 8

non living aspects of viruses?

Answer 8

are non cellular, have no metabolic activity, can’t reproduce outside of host cell.

Question 9

describe actual strucutre of viruses - naked and enveloped

Answer 9

enclosed within a capsid (protein cell) forming a nucleocapsid
like this = naked
enveloped, formed during budding

Question 10

how are naked viruses released?

Answer 10

lysis: infected host cell explodes and virus released – can infect other cells

Question 11

how are enveloped viruses released?

Answer 11

leaves the cell and part of the plasma membrane envelopes it; released as the cell dies.

Question 12

define: prions

Answer 12

infectious particles made of proteins and lacking nucleic acids; they have the same amino acid sequence as noral proteins but their secondary structure is altered – hence, misfolded.
Reproduce by coming into contact with normal proteins, causing them to become prions.