MMB04 Bacterial Growth And Control Of Microbial Growth Flashcards

1
Q

Where are microorganisms usually found on the body

A

On the skin and on mucous surfaces.

They should not be found on or in external organs, blood, lymph and nervous system

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Are microorganisms usually pathogenic or benign

A

Most, but not all pathogens are benign

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

When are mammals exposed to microorganisms

A

Since mamas develop in a sterile environment, they are only exposed to microorganisms after birth from skin contact, feeding and being exposed to the environment

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is colonisation

A

When microorganisms begin to grow after gaining access to host tissues

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Why are microorganisms important in gut health

A

They synthesise important vitamins like B12 and K. Some studies link a healthy gut micro biome to weight loss and mental health

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

How do microorganisms cause infections in mucus membranes

A

They may associate loosely to the mucus membrane
They may adhere strongly to the mucous and epithelial cells
They may invade deeper into the epithelial cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What does infection mean

A

When a microorganisms is established and growing inside a host. This may not always be damaging to the host

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What does disease mean

A

The damage caused to the host by the microorganisms

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What is pathogenicity

A

The ability of a pathogen to inflict damage onto a host

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What causes variation in pathogenicity

A

The identity of the pathogen
The susceptibility of the host

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What is an opportunistic pathogen

A

A pathogen that only causes disease in the absence of the hosts normal resistance

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What is virulence

A

The quantitive measure for a pathogenicity. It is the relative ability for the pathogen to cause disease

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What are exotoxins

A

Toxic proteins released by the pathogen as it grows. They travel from the site of infection to distant areas

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What are the three types of exotoxins

A

Cytolitic toxins
AB toxins
Superantigen toxins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What are cytolytic exotoxins

A

They degrade cytoplasmic membrane integrity possibly causing lysis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What are AB exotoxins

A

Made up of a B subunit and an A subunit. The B subunit binds to the cell membrane receptor which allows A to pass through the membrane and cause damage

17
Q

What are superantigen exotoxins

A

They stimulate large numbers of immune cells resulting in swelling and inflammation

18
Q

What are enterotoxins

A

Special exotoxins that that affect the small intestine

19
Q

What are endotoxins

A

Lipoploysacharaides produced by most gram negative bacteria. They are not secreted and are only released when the cells lyse

20
Q

What is LD50

A

The median lethal dose that can kill 50% of hosts infected

21
Q

What is pasteurisation

A

A process of heat sterilisation invented by Louis Pasteur.
Kills many organisms, but not all so is not a method of sterilisation.
Heat sterilisation will not kill endopsores

22
Q

What is autoclaving

A

Steam heating at 121 degrees C for 15mins at high pressure.
Kills all bacteria including endospores
Sterilises equipment

23
Q

How does UV light kill bacteria

A

Leads to DNA modifications and breaks causing cell death
Used do disinfect surfaces, air and water

24
Q

How does ionising radiation kill microorganisms

A

Generates electrons, hydroxyl radicals, hydride radicals which disrupt DNA, proteins and lipids
Used to sterilise equipment and food

25
Q

How do membrane filters work

A

Made of polymers that create pores too small for bacteria and spores to pass through
Usually used to sterilise liquid in labs