Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

BFI: Biology > Bacteria > Flashcards

Bacteria Flashcards

You may prefer our related Brainscape-certified flashcards:
AP® Biology flashcards Biology 101 flashcards
1
Q

Cell

A

Basic unit of life

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

2 groups based on cellular organisation

A

Prokaryotes - bacteria

Eukaryotes - Animals, plants, fungi, algae

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

Why isn’t a virus a group?

A

It relies on the host’s molecular mechanism

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

What bacteria does not have a cell wall?

A

Mycoplasmas - obligates intracellular parasites

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

Function of cell wall

A

Define shape, gives rigidity + resists turgor pressure

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

Cell wall made up of?

A

Semi - rigid wall composed of peptidoglycan (murein)

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

Mycobacteria

A

Cell wall rich in mycelia acid + PDC

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

What bacteria takes up more gram stain?

A

Gram-positive

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

Transpeptidation

A

process of cross-linking peptidoglycan chains

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

What does PDC monomer consist of>

A 
NAG = N-acetylglycosamine
NAM = N-acetylmuramic acid
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What binds NAG + NAM?

A

Glycosidic acid

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

Gram-positive

A

Thickest bacterium = many interconnecting layers of peptidoglycan (20-80nm)
Teichoic + Lipoteichoic acid is embedded in wall
- they help movement of molecules in + out bacterium
Various protein embedded
- Adhesins = adhere to host
- Enzymes = damage host tissues
- Invasins = invade host cells
Cocci

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

Gram-negative

A

Thinner bacterium - get layers of PDC (2-3nm)
Outer membrane = rich lipopolysaccharide (LPS)
- LPS linked to PDC by lipoprotein anchor
various proteins in outer membrane

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

What has an acid fast wall cell wall

A

Mycobacterium (gram-positive)

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

What stain does mycobacterium take up?

A

Ziehl-Neelsen stain

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

Function of Mycolic acid

A

Disrupt entry of molecules causing slow growth, giving greater resistance to chemical agents + enzymes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Unique chemical structures in prokaryotic cells

A
  • Fimbriae/pili
  • Capsule/slime layers
  • Flagella
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Fimbriae/pili

A

involved in attachment of surfaces - other cells

  • mainly gram-negative
  • coated with proteins
  • communication + exchange of genetic information
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Capsules/slime layers

A

Protection from immune evasion (phagocytosis) + attachment

- Biofilms

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Biofilms

A

Collection of microorganism surrounded by the slime they secrete - attached to inert/living species

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Flagella

A

Cells swim through environment

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Endospores

A

major source of infection - produced when starved or adverse environment
Exists in state of dormancy - persist for long periods of time
Highly resistant to extreme pH, temperature, radiation, desiccation, chemical agents
not all gram-positive bacteria form spores

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What bacterium form spores?

A

Bacillus anthraces
Bacillus cereus
Clostridium difficile
Clostridium tetani

24
Q

Bacterial microflora

A

The bacteria all over the body may not be damaging but protective or beneficial.
Also called microbiome + commensal bacteria
- tend to be low virulence
- loose interaction with epithelial surfaces ( Skin, GI tract)
- essential for normal wellbeing
- kept in balance by host immune responses
- reduce risk of colonization by pathogenic bacteria

25
Q

Exotoxin pathogenicity

A

made by bacteria + secreted out f the bacterium
produce local/systemic infections
different types
Bacteria secrete enzymes + molecules which
- damage immune response molecules
- damage cell + tissue

26
Q

Different types of exotoxins

A

Cytolytic toxins - damage cell membrane
A-B toxins - disrupt protein synthesis
Super antigen - activation of T cell response in antigen absence / diversion of immune response

27
Q

Different types of exotoxins

A

Cytolitic toxins - damage cell membrane
A-B toxins - disrupt protein synthesis
Super antigen - activation of T cell response in antigen abscence / diversion of immune response

28
Q

Endotoxins pathogenicity

A 
Lipopolysaccharide in gram-negative (released upon lysis of bacterial cell) + contains
- lipid A
- core polysaccharide
- O-polysaccharide
Endotoxins cause:
- immune system activation
- fever/diarrhoea
- release cytokines
- inflammation
29
Q

What has a similar response as endotoxins pathogenicity?

A

Teichoic acids in gram-positive

30
Q

Environmental changes where microbes are found to cause bacterial infections

A

Invasion of wound
Antibiotic therapy
Nosocomial infections
Latrogenic infections

31
Q

Incidental exposure to cause bacterial infections

A 
GI infections
- E.coli
- Campylobacter
- Vibrio Cholera
Person-person
- Neisseria meningtidis
- Chlamydia trachmatis
- Mycobacterium tuberculosis
- Neisseria gonorrhoea
Environmental
- Clostridium retain lives in soil
- Legionella = failure to maintain air condition
32
Q

How do we identify?

A

Samples

Methods

33
Q

Methods of identification

A

Microscopy, culture, serology, molecular

34
Q

Samples of identification

A

Timing, biopsy, environmental, body fluids, collection/transport

35
Q

Symptoms of infection depend on

A

1) Site of infection
2) No. of pathogens/site of inoculums
3) ability of pathogens to colonise host
4) Virulence factors produced toxins
5) Ability to evade immune response
6) Age/condition of host

36
Q

Asymptomatic carriers

A

Carry pathogenic bacteria but no sign of disease

37
Q

Infectiousness

A

Ease of spread in a population

38
Q

Pathogenicity

A

Ability to cause disease

39
Q

Pathogenicity factors

A

e.g. adherence, colonisation, invasion, toxins

40
Q

Virulence

A

Power to cause severe disease e.g. toxin, resistance

41
Q

Intoxication/food-poisoning

A

Ingestion of bacterial-derived toxin, often in absence of bacterium e.g. toxin in/on food

42
Q

Infection

A

Microorganism established, growing and/or spreading on or within host

43
Q

Attached to each NAM is…

A

5 amino acids

- but 1 amino acid is removed during assembly = NAM-tetrapeptide

44
Q

How to reduce risk of colonization by pathogenic bacteria

A

Modify local pH
Block host binding sites
Secrete toxic metabolites

45
Q

What can start a systemic cellular responsed

A

Bacterial derived toxins

46
Q

Disease

A

Recognisable + defined damage/injury to host that impairs host function

47
Q

Biological agent

A

Any microorganism, cell culture or toxin able to enter human body + cause harm

48
Q

Typing of E.coli strain O157:H7

A

Entero-haemorrhagic E.coli
170 O antigens (LPS)
100 K antigens (Capsule)
50 H antigens (Flagella)

49
Q

How can bacterial infections arise

A

Incidental exposure/poor or inadequate hygiene/precautions
- GI infections
- person - person
- Environmental
Environmental change where microbe is found
- Wound invasion
- Antibiotic therapy
- Nosocomial infections
- Latrogenic (caused by doctors) infection

50
Q

How does Clostridium difficile spread

A

Poor hygiene + inadequate disinfection

51
Q

How can resistance arise in Clostridium difficile

A

Inappropriate use of antibiotics + some bacteria have natural resistance (waxy cell wall of Mycobacteria disrupt entry of antibiotics)

52
Q

Routes of entry of into host, cycling + transmision

A

1 )Exposure

2) Adherence
3) Invasion
4) Colonisation + growth
5) Toxicity 6) Tissue damage + disease
5) Invasiveness 6) Tissue damage + disease / further exposure back to (1)

53
Q

Cytolytic toxin

A

Disrupt cell membrane

54
Q

A-B toxins

A

disrupt protein synthesis

55
Q

Super-antigen toxins

A

activate T cell response in antigen absence

BFI: Biology (9 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions