Communicable Disease, Prevention and Immunity - Types of Pathogens Flashcards
(18 cards)
what are the four types of pathogen
- bacteria
- viruses
- protoctista
- fungi
how are bacteria classified
- by shape
- by cell walls
how are bacteria classified by cell walls
- gram positive (e.g MRSA, thicker peptidoglycan cell wall)
- gram negative (e.g E coli, thin peptidoglycan layer)
which kingdom do bacteria belong to
prokaryote
describe bacteria reproduction
can reproduce rapidly - every 20 mins
what do bacteria produce
toxins
what are the effects of toxins
- break down plasma membranes
- damage and inactivate enzymes
- prevent mitosis
describe viruses
non living pathogens, also parasites
how big are viruses
0.02-0.3 micrometres (x50 smaller than bacteria)
describe the genetic material of viruses
surrounded by a protein coat
how do viruses reproduce
- invade living cells, and take over the host cell’s genetic machinery
- they cause the cell to manufacture more copies of the virus and the cell will eventually lyse, releasing the new viruses
what are bacteriophages
viruses that infect bacteria
do viruses evolve rapidly
yes
describe protoctista
- eukaryotes
- single celled organisms and colonies of cells
- some act as pathogens and parasites, using animals as their host
what do some protoctista need to transfer them into their hosts
a vector
describe fungi
- eukaryotic, often multicellular
- many are saprophytes (secrete enzymes onto dead/decaying matter)
- some are parasites (pathogenic fungi)
what happens when fungi affect leaves
photosynthesis stops
what happens when fungi reproduce
millions of spores are produced, which can cause the fungus to spread rapidly and widely through crop plants, causing devastation
