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Flashcards in Microbiology Deck (47)
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1
Q

What is microbiology

A

The study of microorganisms

2
Q

Classification of microorganisms

A

Fungi
Bacteria
Viruses

3
Q

Conditions needed for the growth of microorganisms

A
Food (saprophytic and parasitic)
Oxygen (aerobic, anaerobic and facultative)
Temperature
Moisture
Ph level 
Time
4
Q

What are saprophytic microorganisms

A

They feed on non living matter eg decaying plants

5
Q

What are parasitic microorganism

A

They feed on living matter eg animals/human

6
Q

What are aerobic microorganisms

A

Require oxygen

7
Q

What are anaerobic microorganisms

A

Don’t require oxygen

8
Q

What are facultative microorganisms

A

Can grow with or without oxygen

9
Q

Microorganisms grow on foods with what water activity

A

0.80 or higher

10
Q

Thermophilic means

A

Very hot environment

11
Q

Examples of saprophytic fungi

A

Mushrooms

Mould

12
Q

Examples of parasitic fungi

A

Ring worm,

Athletes foot

13
Q

Use of mould

A

Manufacture of food stuff eg. Cheese

Manufacture of medicine eg penicillin

14
Q

Conditions needed for the growth of mould

A

Food (they’re saprophytic)
Oxygen (they’re aerobic so will grow on the surface of foods)
Temperature (mesophilic (medium), they slow down at lower temperatures and are destroyed at higher temperatures)
Moisture (humid is best)
Ph (slightly acidic)
Time (24-48 hours)

15
Q

How many cells in a mould spore

A

1

16
Q

Cycle of mould

A
Spore
Grows hypha 
Once in right condition grows hyphae 
Hyphae all become intertwined into mycelium 
Hyphae grow upwards from mycelium
17
Q

Does mould sexually or asexually reproduce

A

Both

18
Q

Tow types of moulds

A

Phycomycetes

Ascomycetes

19
Q

Example of large fungi

A

Mushrooms

20
Q

Poisonous mushroom

A

Death cap

21
Q

Alright mushroom

A

Truffle

22
Q

Reproduction of mushrooms

A
Start as single spore
Hyphae grow
Mycelium form
Hyphae bunch up and grow upwards into a stalk
Cap forms at top
Underside has gills
When ripe, mushrooms release spores
Spores are dispersed
23
Q

Conditions needed for the growth of yeast

A
Food; saprophytic 
Oxygen; facultative
Temperature; mesophilic 
Moisture 
Ph level; slightly acidic (4-6)
Time
24
Q

Reproduction of yeast name

A

Asexually

Budding

25
Q

Explain budding

A

When conditions are favourable, parent cell develops bud
Nucleus splits in two and moves towards bud
One goes into bud
Cell wall develops
2 separate now
Many buds will produce

26
Q

Advantages of fungi

A
Protein;alternative foods 
Edible
Cheese production
Antibiotics
Bread and brewing
Vitamin supplements
27
Q

Disadvantages of fungi

A

Food spoilage
Poisonous
Human diseases
Animal disease

28
Q

Conditions needed for growth of bacteria

A

Food: both saprophytic and parasitic
Oxygen: aerobic, anaerobic and facultative
Temperature:all 4
Moisture
Ph: 6-7 (extreme heats or ph inhibits growth)
Time (double every 20 mins)

29
Q

How do bacteria reproduce

A

Binary fission

30
Q

Explain binary fission

A
Cell elongates
Nucleus splits in two
Spread apart
Wall forms
Two new cells
31
Q

Stages in bacteria growth

A

Lag phase
Log phase
Stationary phase
Decline phase

32
Q

What happens in lag phase

A

Little growth of bacteria as they are adapting to their environment

33
Q

What happens in log phase

A

Bacteria multiply quickly as are in ideal conditions

34
Q

What happens in stationary phase

A

No increase in growth
Production of new bacteria is compensated for by death of other bacteria
Plateau
Reason for death: lack of food, space and oxygen causes competition

35
Q

Decline phase

A

Greater amount dying than being produced.

Some survive by producing endospores

36
Q

What are endospores

A

Tough, dormant cells that form around DNA of a bacterial cell to suirvue

37
Q

How to endospores form

A

DNA duplicates
Endospore forms around one
Rest of cell disintegrates and endospore remains dormant
Reproduce by binary fission when in suitable conditions

38
Q

Example of endotoxins

A

Salmonella

39
Q

Example of exotoxins

A

Staphylococcus aureus

40
Q

Shapes of bacteria

A

Coccus (round) eg pneumonia
Bacillus (rod) eg salmonella
Curved and spiral eg cholera

41
Q

Gram positive stain

A

Purple

42
Q

Gran negative stain

A

Pink

43
Q

Two ways of classifying bacteria

A

Shape

Gram staining

44
Q

Features of a gram positive cells

A

Thick cell wall
No flagella
Produces spores
Low resistance to antibiotics

45
Q

Example of a gram positive

A

Streptococci

46
Q

Gram negative features

A

2 thin layers
Flagella
No spore production
High resistance to antibiotics

47
Q

Example of gram negative

A

E. coli