Bacteria (Monera) Flashcards Preview

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Flashcards in Bacteria (Monera) Deck (48)
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1
Q

What is the function of ribosomes in bacterial cells?

A

They are the site of protein synthesis

2
Q

Describe the bacterial cell wall.

A

Main function- to prevent osmotic bursting of the cell

Cell wall is permeable to water, solutes and small insoluble particles

Rigid extracellular structure (no cellulose)

3
Q

What is the function of the slime layer/capsule?

A

Provides protection.

4
Q

Do bacteria have membrane enclosed organelles?

A

No.

The ribosomes, bacterial chromosome and plasmid are suspended.

5
Q

What is a flagellum?

A

-Allows movement in search of food or more suitable growing conditions.

6
Q

Is the flagellum present in all bacteria?

A

No.

7
Q

What is a plasmid?

A
  • Small circle of DNA

- Carries genes of benefit to the bacterium eg. resistance to antibiotics

8
Q

What is the function of the mesosome?

A
  • Infolding of cell membrane

- Involved in aerobic respiration

9
Q

What is the function of the storage granules?

A

To store food or waste.

10
Q

What factors affect the growth of bacteria?

A
  • Temperature

- Oxygen concentration

11
Q

What do aerobic bacteria need for respiration?

A

-Need oxygen

12
Q

Do anaerobic bacteria need oxygen to respire?

A

No, they do not need oxygen.

13
Q

What can facultative anaerobes do?

A

-Can respire with or without oxygen

14
Q

What can obligate anaerobes not do?

A

They cannot not use oxygen and do not grow if oxygen is present.

15
Q

Does high pressure stop bacterial growth?

A

Yes, however some bacteria can withstand high pressure.

16
Q

How are endospores formed?

A

These are formed when the bacterial chromosome replicates.

17
Q

What happens to the endospore when there is favourable conditions?

A

-The spores absorb water, break their walls and reproduce by binary fission.

18
Q

Name two economic benefits of bacteria.

A
  • Produce antibiotics

- Produce yogurt and cheese

19
Q

Name two harmful economic effects of bacteria.

A
  • Causes food poisoning

- Causes cholera

20
Q

What are antibiotics?

A

-Are chemicals produced by micro-organisms that stop the growth of, or kill other micro-organisms without damaging human tissue.

21
Q

How do bacteria develop a resistance to antibiotics?

A

They mutate

22
Q

Can antibiotics be abused?

A
  • Yes

- Repeated exposure to antibiotics enables resistant strains of bacteria to evolve.

23
Q

What can cause bacteria to become resistant?

A

Not taking the full course of antibiotics once prescribed can also cause resistant bacteria to develop.

24
Q

What are pathogenic bacteria?

A

Are bacteria that cause disease

25
Q

What kingdom do bacteria belong to?

A

Kingdom Monera

26
Q

Are bacteria eukarotic or prokaryotic?

A

They are prokaryotic

27
Q

Describe the lag phase.

A
  • Adapting to new environment
  • Numbers remain constant
  • Bacteria are producing the enzymes necessary to digest the nutrients
  • The rate of growth begins to increase towards the end of this phase
28
Q

Describe the log phase.

A
  • Numbers increase rapidly

- Ideal conditions, plenty of food, moisture, space and oxygen

29
Q

Describe the stationary phase.

A
  • No increase in bacterial numbers
  • New bacteria = number of dying bacteria
  • Lack of food, space, moisture
  • Build up of toxins
30
Q

Describe the decline phase.

A
  • Death phase

- Rapid decline in bacterial numbers

31
Q

Describe the survival phase.

A

-Small number of bacteria survive by remaining dormant as endospores.

32
Q

What is a bioreactor?

A

Is a vessel in which biological reactions take place

33
Q

What are the two main methods of food processing?

A
  • Batch food processing

- Continuous flow food processing

34
Q

Describe batch food processing.

A

-A fixed amount of sterile nutrient is added to the micro-organisms in the bioreactor.

35
Q

What happens at the end of the batch food processing.

A

-At the end of production the bioreactor is cleared out. The product is separated from the rest of the solution and is purified.

36
Q

What happens in continuous flow food processing?

A

-Nutrients are continuously fed into the bioreactor

37
Q

What phase in the growth curve is continuous flow food processing kept at?

A

Log phase

38
Q

What does unicellular mean?

A

They are made up of only one cell.

39
Q

What are three main types of bacteria?

A
  • Rods
  • Round (coccus)
  • Spiral
40
Q

Give an example of a rod shaped bacteria.

A

E.coli

41
Q

Give an example of a round shaped bacteria.

A

Streptococcus

42
Q

Give an example of a spiral shaped bacteria.

A

Syphilis

43
Q

How do bacteria reproduce?

A

Produce by binary fission

44
Q

How do bacteria asexually reproduce?

A
  • DNA stand replicates
  • How there is 2 strands of DNA
  • The bacterial cell elongates. A strand of DNA moves to each end of the cell
  • The cell splits and two identical cells are formed.
45
Q

When are endospores formed?

A

Formed when conditions become unfavourable.

46
Q

How long does an endospore take to form?

A

About 8 hours

47
Q

Describe the formation of the endospore.

A
  • Bacterial chromosome replicates
  • One of the strands of DNA becomes enclosed by a tough walled endospore formed within the bacterial cell.
  • Parent cell breaks down.
  • Endospore remains dormant
48
Q

Where are chemosynthetic involved in?

A

-Parts of the nitrogen cycle