WEEK 3 - Microbiology Flashcards
1
Q
What are microorganisms?
A
- Organisms too small to be seen with naked eye
- Largest group of organisms
- Occupy every conceivable environment
- Most beneficial
2
Q
What are the two types of microorganisms?
A
- Cellular organisms
- E.g. Bacteria, Archaea and Fungi, protists, helminths
- Acellular infectious agents
- E.g. Viruses and Prions
3
Q
What is bacteria (and archaea)?
A
- Prokaryotes
- They lack internal membranes such as a nuclear membrane around their DNA
- Human, plant, fungi, protists and helminths cells are eukaryotes because their DNA is enclosed in a nuclear membrane
4
Q
What is nomenclature?
A
- Have a two-part scientific name, consisting of a genus and a specific descriptive name
- e.g., Escherichia (genus) coli (species)
- Both words spelt out in full when first used
- After that the genus may be abbreviated = E. coli
- Name italicized
5
Q
What is the structure of bacteria and archaea?
A
- Unicellular
- One linear or circular chromosome (nucleoid)
- Most have a cell wall and glycocalyx
- Everywhere sufficient H2O
6
Q
What is diplo?
A
pairs
7
Q
What is strepto?
A
chains
8
Q
What is staphylo?
A
clusters
9
Q
What is the bacterial cell wall?
A
Rigid structure outside plasma membrane to resist dehydration (shrinking) or swelling (bursting)
10
Q
What is the two main types of bacterial cell wall?
A
- Gram–positive
- Gram–negative
11
Q
What is gram-positive?
A
- Stain purple
- Thick peptidoglycan layer (sugars linked by amino acids)
- Sensitive to penicillin and lysozyme
12
Q
What is gram-negative?
A
- Stain pink
- Thin peptidoglycan layer
- Additional outer membrane (phospholipids and lipopolysaccharides (endotoxins)
- Not sensitive to penicillin and lysozyme
13
Q
What are other bacterial features?
A
Glycocalyx
14
Q
What is flagellum?
A
Move by flagellum (one or more)
15
Q
What is fimbriae?
A
Communicate and stick by fimbriae (many)
