Bacteria (Monera)

Question 1

What is the function of ribosomes in bacterial cells?

Answer 1

They are the site of protein synthesis

Question 2

Describe the bacterial cell wall.

Answer 2

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)

Question 3

What is the function of the slime layer/capsule?

Answer 3

Provides protection.

Question 4

Do bacteria have membrane enclosed organelles?

Answer 4

No.

The ribosomes, bacterial chromosome and plasmid are suspended.

Question 5

What is a flagellum?

Answer 5

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

Question 6

Is the flagellum present in all bacteria?

Answer 6

No.

Question 7

What is a plasmid?

Answer 7

• Small circle of DNA

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

Question 8

What is the function of the mesosome?

Answer 8

• Infolding of cell membrane

- Involved in aerobic respiration

Question 9

What is the function of the storage granules?

Answer 9

To store food or waste.

Question 10

What factors affect the growth of bacteria?

Answer 10

• Temperature

- Oxygen concentration

Question 11

What do aerobic bacteria need for respiration?

Answer 11

-Need oxygen

Question 12

Do anaerobic bacteria need oxygen to respire?

Answer 12

No, they do not need oxygen.

Question 13

What can facultative anaerobes do?

Answer 13

-Can respire with or without oxygen

Question 14

What can obligate anaerobes not do?

Answer 14

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

Question 15

Does high pressure stop bacterial growth?

Answer 15

Yes, however some bacteria can withstand high pressure.

Question 16

How are endospores formed?

Answer 16

These are formed when the bacterial chromosome replicates.

Question 17

What happens to the endospore when there is favourable conditions?

Answer 17

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

Question 18

Name two economic benefits of bacteria.

Answer 18

• Produce antibiotics

- Produce yogurt and cheese

Question 19

Name two harmful economic effects of bacteria.

Answer 19

• Causes food poisoning

- Causes cholera

Question 20

What are antibiotics?

Answer 20

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

Question 21

How do bacteria develop a resistance to antibiotics?

Answer 21

They mutate

Question 22

Can antibiotics be abused?

Answer 22

• Yes

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

Question 23

What can cause bacteria to become resistant?

Answer 23

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

Question 24

What are pathogenic bacteria?

Answer 24

Are bacteria that cause disease

Question 25

What kingdom do bacteria belong to?

Answer 25

Kingdom Monera

Question 26

Are bacteria eukarotic or prokaryotic?

Answer 26

They are prokaryotic

Question 27

Describe the lag phase.

Answer 27

- 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

Question 28

Describe the log phase.

Answer 28

- Numbers increase rapidly | - Ideal conditions, plenty of food, moisture, space and oxygen

Question 29

Describe the stationary phase.

Answer 29

- No increase in bacterial numbers - New bacteria = number of dying bacteria - Lack of food, space, moisture - Build up of toxins

Question 30

Describe the decline phase.

Answer 30

- Death phase | - Rapid decline in bacterial numbers

Question 31

Describe the survival phase.

Answer 31

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

Question 32

What is a bioreactor?

Answer 32

Is a vessel in which biological reactions take place

Question 33

What are the two main methods of food processing?

Answer 33

- Batch food processing | - Continuous flow food processing

Question 34

Describe batch food processing.

Answer 34

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

Question 35

What happens at the end of the batch food processing.

Answer 35

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

Question 36

What happens in continuous flow food processing?

Answer 36

-Nutrients are continuously fed into the bioreactor

Question 37

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

Answer 37

Log phase

Question 38

What does unicellular mean?

Answer 38

They are made up of only one cell.

Question 39

What are three main types of bacteria?

Answer 39

- Rods - Round (coccus) - Spiral

Question 40

Give an example of a rod shaped bacteria.

Answer 40

E.coli

Question 41

Give an example of a round shaped bacteria.

Answer 41

Streptococcus

Question 42

Give an example of a spiral shaped bacteria.

Answer 42

Syphilis

Question 43

How do bacteria reproduce?

Answer 43

Produce by binary fission

Question 44

How do bacteria asexually reproduce?

Answer 44

- 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.

Question 45

When are endospores formed?

Answer 45

Formed when conditions become unfavourable.

Question 46

How long does an endospore take to form?

Answer 46

About 8 hours

Question 47

Describe the formation of the endospore.

Answer 47

- 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

Question 48

Where are chemosynthetic involved in?

Answer 48

-Parts of the nitrogen cycle