Introduction to microbiology

Question 1

What are the major differences between prokaryotes and eukaryotes?

Answer 1

Eukaryotic cells have a membrane-bound nucleus and prokaryotic cells do not.
Genetic material in prokaryotic cells is loose.

Question 2

How many microbes are in/ on the human body?

Answer 2

100 x 10^14

Question 4

How do we name bacteria?

Answer 4

Genus name: capital letter, italics, Latin/ Greek descriptive eg. Staphylococcus/ streptococcus

Followed by species name: starts with lower case, italics, Latin eg. Aureus, pyogenes

Genus species eg. Staphylococcus aureus

Question 5

What staining do we use for bacteria and what is the meaning?

Answer 5

GRAM staining
Gram Positive: stains PURPLE eg. staphylococcus aureus
Gram Negative: stains PINK eg. Escherichia Coli
Gram staining helps to identify genus level.

Question 6

Viruses

Answer 6

Akaryotic
Size: 0.01-0.2 um
Composed of: nucleic acid and protein coat

Question 7

Fungi

Answer 7

Size: 2um-20cm
Eukaryotic cell structure
unicellular (yeast) or multicellular (mushrooms)

Question 8

Protozoa

Answer 8

Size: 1-200 um
Eukarytoic cellular organisation but no cell wall
ingest solid food particles

Question 9

How are microbes used in food?

Answer 9

spoilage, preservation, source of food, food production, food poisoning
eg. quorn= mycoprotein from fungal mycelium

Question 10

What bacteria are used in the food industry?

Answer 10

Corynebacterium glutamicum- lysine, glutamic acid
Erwinia sp. - pectinase
Bacillus sp.- amylase
Acetobacter sp.- vinegar
Lactobacillus sp. - lactic acid, yoghurt

Question 11

What is cholera?

Answer 11

Caused by vibrio cholerae (gram negative rod bacterium).
Classic disease of poverty and poor sanitation
Transmission: faecal-oral through contaminated water
Causes rice-water stool causing death by shock due to dehydration

Question 12

Why are microbes good for us?

Answer 12

inhibit pathogens, produce vitamins, induce antibody production, we use it to process sewage.