Monera (Bacteria) Flashcards

1
Q

micro organism definition

A

a small living thing

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2
Q

bacteria are…

A

unicellular
microscopic
prokaryotic
heterotroph and autotroph

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3
Q

prokaryotic definition

A

do not have a nucleus or cell enclosed organelles

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4
Q

shape of bacteria

A

round
rod
spiral

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5
Q

examples of bacteria

A

pneumonia
ecology
syphillus
tuberculosis
cholera

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6
Q

capsule function

A

further protection

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7
Q

plasmid function

A

resistance to drugs/antibiotics and used in genetic engineering

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8
Q

flagella function

A

movement

motile

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9
Q

are bacteria motile?

A

yes — flagella

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10
Q

How do bacteria reproduce?

A

Asexually, by Binary Fission

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11
Q

Binary Fission steps

A
  1. cell reaches a certain size & DNA strand replicates itself
  2. Now 2 identical strands of DNA
  3. Cell ELONGATES with a strand of DNA attached to each side
  4. Cell splits into 2 similar sized cells
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12
Q

Mutations in Bacteria

A

Offspring genetically identical.
Short life span of bacteria mean that any new variation produced by a mutation can be passed quickly to a large number of bacteria.
This is how bacteria evolve and become resistant to new antibiotics.

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13
Q

Nutrition in Bacteria
Heterotrophic : Saprophytic

A

Eg: Bacteria of decay

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14
Q

Nutrition in Bacteria
Heterotrophic : Parasitic

A

Eg: Bacillus anthracis

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15
Q

Nutrition in Bacteria
Autotrophic : Photosynthetic

A

Eg: purple sulphur bacteria

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16
Q

Nutrition in Bacteria
Autotrophic : Chemosynthetic

A

Eg: Nitrifying bacteria

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17
Q

Photosynthetic bacteria definition

A

Use light energy to make food
eg: purple sulphur bacteria

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18
Q

Chemosynthetic bacteria definition

A

Use energy from chemical reactions to make food
eg: nitrifying bacteria

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19
Q

Saprophytic bacteria definition

A

live off dead plants / animals (carbon cycle)
eg: bacteria of decay

20
Q

Parasitic bacteria definition

A

take food from live host, some cause disease
eg: bacillus anthracis (causes anthrax)

21
Q

Factors affecting growth of bacteria
(limiting factors)

A

Temp
pH
Oxygen Conc
External solute Conc
Pressure

22
Q
  1. Temperature
A

most bacteria grow well between 20/30°C
some can tolerate higher temps without enzymes being denatured
low temps slow down rate of reaction of enzymes resulting in SLOWER GROWTH

23
Q
  1. pH
A

If bacteria is placed in an unsuitable pH it’s enzymes will become denatured.
Most bacteria grow at pH7
Some can tolerate very low/high pH values.

24
Q
  1. Oxygen Concentration
A

Aerobic bacteria need oxygen for respiration (eg: streptococcus) (this is why oxygen is sometimes bubbled through bioreactors)
Anaerobic bacteria don’t require oxygen to respire.
- Faculative anaerobes can respire with or without (eg: ecoli)
- Obligate anaerobes can only respire in the absence of oxygen (eg: clostridium tetani)

25
Q

Aerobic bacteria

A

need oxygen to respire

26
Q

Anaerobic Bacteria

A

don’t need oxygen to respire

27
Q

Faculative anaerobes

A

can respire with or without oxygen

28
Q

Obligate anaerobes

A

can only respire without

29
Q
  1. External solute concentration
A

Bacteria can gain or lose water by osmosis
If external solute conc is
Higher than the bacterial cytoplasm - water will move out of bacteria, causing dehydration (tinned fish, fruits)
Lower than the bacterial cytoplasm, water will enter bacteria (cell wall prevents bursting)

30
Q
  1. Pressure
A

growth of bacteria is inhibited by high pressures
some can withstand high pressures
Pressure tolerant bacteria for use in bioreactors can be formed by genetic engineering techniques (GMO)

31
Q

Economic importance of bacteria
Beneficial

A

lactobacillus bulgaricus converts milk to yogurt and cheese
antibiotics can be formed
bacteria are active in carbon and nitrogen cycles

32
Q

Economic importance of bacteria
Harmful

A

pathogenic bacteria can cause disease in humans and animals (pathogens)
bacteria can cause food spoilage
bacteria can cause tooth decay

33
Q

pathogen definition

A

organisms that cause disease

34
Q

Lag phase

A

Bacterial cells adapting to new conditions.
They’re producing enzymes to digest the nutrients
Rate of growth begins to increase at end of lag

35
Q

Log phase

A

Rapid period of growth due to:
bacteria developing enzymes and there are plenty of nutrients
lack of waste products being produced

36
Q

Stationary phase

A

Rate of growth levels off
Death rate equals birth rate

lack of food, space, moisture and oxygen

37
Q

Death phase

A

Durina this phase more bacteria are dying than are being produced.
This is because :
- few nutrients are left
- bacteria are poisoned by the waste produced in such large numbers
- This the rate of grouth is falling

38
Q

favourable conditions for bacteria growth

A

O2
Food
Space
Moisture
PH
Temp

39
Q

Endospore formation

A

Occurs during binary fission
1. DNA replicates itself
2. One of the new strands of Dna becomes enclosed in a tough walled capsule called an endospore, formed inside the parent cell.
3. Parent cell breaks down
4. Endospores can remain dormant for long time
5. When conditions are favourable new bacteria can be formed again and continue to reproduce

40
Q

Bioreactors definition

A

a large, stainless steal vessel which biological reactions take place in the presence of micro organisms.

41
Q

Batch food processing

A
  1. A fixed amount of nutrient is added to bioreactor at start
  2. Micro organisms go through lag and log and stationary phase where most product is formed
  3. Product is formed over short period of time.
  4. Process starts again
42
Q

Continuous flow processing

A
  1. Nutrients added all the time
  2. Micro organisms mainly go through log phase where most product is formed
  3. Long period of time
43
Q

Antibiotics

A

antibiotics are chemicals produced by micro organisms that stop growth or kill other micro organisms without damaging human tissue (NOT VIRUSES)

44
Q

Antibiotic resistance

A

Occurs during binary fission
2. mutations in bacteria genes cause antibicic resistance
3. This is known as natural
selection
4. These changes in the genes can be passed on quickly to new bacteria » surviving chains multiply
5. This leads to build up of an antibiotic resistant population.

45
Q

how does antibiotic resistance occur

A

misuse of antibiotics