Microorganisms Flashcards
Define a microorganism?
- Microscopic organism –> have to use a microscope.
- Mostly unicellular.
- Includes: bacteria, fungi, protozoa, algae and viruses.
What is protozoa?
Malaria caused by plasmodium spp.
- transmitted by mosquito.
- complex lifespan.
- infects red blood cells.
What is another protozoa?
Entamoeba histolytica –> causes diarrhoea or amoebic dysentery.
- transmitted from eating/drinking something contaminated with infected faeces.
What are fungi’s?
Organisms that grow by decomposing and absorbing material.
- non motile –> don’t move.
How is fungus classified?
Based on their structure.
What do fungi use to reproduce?
Spores (single cells)
Do fungi always cause harm?
Not always, not always pathogenic.
What are the classification for bacteria shapes?
1) . Bacilli (rod shaped).
2) . Cocci (sphere).
3) . Spiral.
What are the classifications for the bacteria clusters?
1) . Diplo (2 joined).
2) . Strepto (chains).
3) . Staphylo (grapelike cluster).
How are bacteria classified via their colour?
1) . Gram positive (purple/blue).
2) . Gram negative (pink/red).
What is an example of bacteria when the classifications are put together?
1). Staphylococcus =
- grapelike cluster.
- sphere.
2). Streptococcus =
- chains.
- sphere.
How do bacteria divide?
Binary fission –> doubling their number.
Is binary fission a sexual or asexual process?
Asexual.
What is binary fission?
Where bacteria can divide, double their size and replicate their chromosome.
What is bacteria spore formation?
- When vegetative form of bacteria experience unfavourable conditions.
- Spores are resistant; to extreme temperatures and many chemicals.
Why do bacteria form spores?
Because bacterial spores can withstand many conditions, keeping the bacteria alive.
What are commensal organisms?
Bacteria benefit from the host =
- host isn’t harmed.
- organism could be a pathogen if it enters another area of the body.
What is normal flora?
Populations of organisms that live in various parts of the body, but do not cause disease.
What is mutualism?
When both host and microorganism benefit.
What is an example of mutualism?
Lactobacillus =
- maintains the pH of the vagina.
- inhibits growth of potentially harmful fungi which causes thrush.
What are the characteristics of viruses?
- Smaller than bacteria.
- Contains small amount of nucleic acid.
- May be enveloped (lipid/protein structure) or non-enveloped.
- Different shapes.
- Uses its host to replicate and cannot replicate outside of host cells.
What is the protective protein coat of a virus called?
Capsid.
