Introduction to bacteria Flashcards

1
Q

What colour do gram positive cells stain

A

Purple

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

What colour do gram negative cells stain

A

red

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

What 3 shapes do bacteria exist as

A

Coccus
Bacillus
Spiral

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

What is a coccus shape bacteria

A

Spherical

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

What is a Bacillus shape bacteria

A

Rod

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

What size is bacteria

A

Most bacteria range from 0.2–2.0 µm

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

How do bacteria replicate

A
Binary fission, 
Asexual replication (DNA doubles and cell divides)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Why do gram negative cells loose colour when stained

A

as lipopolysaccharide dissolves crystal violet stain, so bacterium remain red

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

What is bacteria conjugation

A

Bacteria direct exchange of plasmids (genes)

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

What bacteria have plasmids

A

resisting bacteria

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

What layer does gram negative have

A

lipopolysaccharide

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

What causes genetic variation

A

spontaneous mutation

transfer of DNA

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

Main function of peptidoglycan

A

Shape and strength

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

main function of lipopolysaccharide

A

Strong immune response

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

When does spore forming occur

A

when conditions become adverts and nutrient run out

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

What happens in spore forming

A
DNA divided into two copies 
developing spore engulfed 
Peptidoglycan forms a cortex around developing spore 
lytic enzymes destroy mother cell 
Mature spore cell released
17
Q

In spore forming bacteria change from once cell to another why?

A

To survive in adverse environmental conditions

18
Q

After conjugation what are both bacteria called and what is present in both

A

F+ cells and both contain identical copies of plasmids

19
Q

What is a bacteriophage

A

Virus that parasites a bacterium, injecting and reproducing in it

20
Q

What is the lysogenic cycle

A

when material is injected with the DNA from the bacteriophage

21
Q

What are the three ways bacteria exchange DNA

A

transformation
transduction
Conjugating

22
Q

What is bacterial transduction

A

viruses carry bacterial genes from one bacterium to another

23
Q

What is bacterial transformation

A

the bacterium takes up of foreign DNA from its surroundings i.e. dead bacterias DNA

24
Q

What is MacConkeys Agar

A

Specialised bacterial growth medium selective for gram negative

25
Why is MacCokeys agar selective and differential
Inhibits growth of Gram positive | and differentiates between which Gram negative bacteria are lactose fermentors
26
What does MacCokeys agar contain
Bile salts and crystal violet | Lactose and neutral red ph indicator
27
What colour does agar turn in the presence of gram negative lactose fermentor
pink
28
What do you find on the cell surface of bacteria
Plasma membrane penicillin binding site peptidoglycan lipopolysaccharides
29
Function of peptidoglycan (murein)
Strength and shape | counteracts high osmotic pressure
30
What is frimbraie
thread like projections used for adherence
31
What is used to identify strains within a species
DNA typing techniques
32
What do strains of species have
similar characteristics
33
Naming bacteria follows what principle
Genus is mentioned then the species
34
whats the genus and whats the species Staphylococcus aureus
Staphylococcus - genus | aureus - species
35
How does bacteria conjugation occur aka function of plasmids
transfer resistance from one bacteria to another via the formation of a PILUS; a bridge between two bacterial cells that is used for communication