Brainscape's Knowledge GenomeTM

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


See full index

ESA 1 Revision > TOB Session 4 > Flashcards

TOB Session 4 Flashcards

Bacteria and Viruses

1
Q

What is infection?

A

The multiplication / colonisation of a pathogenic microbe in a susceptible host with associated dysfunction/damage.

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

What causes infection?

A

Pathogenic microbes. The agent must be shown to be present in every case of the disease by isolation in pure cultre. The agent must not be found in cases of other disease. It must be capable of producing disease on its own. NECESSARY & SPECIFIC.

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

Why are some people more susceptible to infection than others?

A
  • Weakened immune system
  • Poor nutrition
  • Poor living conditions
  • Bad healthcare
  • Genetic predisposition
  • Lifestyle
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What three things influence the outcome of an infection?

A
  1. The immune system of the host
  2. The affected body system(s)
  3. Drugs/antibiotics used
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Compare and contrast bacteria and viruses.

A

Bacteria do not have capsids, Viruses can have capsids.
Neither bacteria nor viruses have membrane bound organelles.
Bacteria can have pili or flagella, viruses do not.
Viruses can have reverse transcriptase, bacteria do not.
Bacteria have circular DNA as well as RNA, Viruses have either one.

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

What are the differences and similarities between bacteria and eukaryotes?

A

Bacteria have peptidoglycan or lipolysaccharide cell walls, eukaryotes have no cell wall.
Neither bacteria nor eukaryotes have a capsid.
Eukaryotes have membrane bound organelles, bacteria do not.
Eukaryotes have a nucleus, bacteria have circular DNA.
Bacteria have pili or flagella, eukaryotes do not.
Neither has reverse transcriptase.

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

Describe the differences and similarities between eukaryotes and viruses.

A

Viruses do not have organelles, eukaryotes do.
Viruses can have capsids, eukaryotes cannot.
Viruses have DNA or RNA, Eukaryotes have both.
Neither have pili or flagella
Viruses can have reverse transcriptase, eukaryotes cannot.

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

What is a Gram Stain?

A

Gram stains let us detect and classify most bacteria as Gram positive or Gram negative.

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

What colour do Gram stains stain?

A

Gram negative bacteria stain red whereas Gram positive bacteria stain blue.

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

How does a Gram stain work?

A

Positively charged crystal violet binds to negatively charged cell components. It then forms a large molecular complex with iodine when added. Acetone or methanol extract the complexes through Gram negative cell walls but not through gram positive cell walls. A red dye is then used to stain the unstained Gram negative cells.

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

What are acid fast stains for?

A

They allow us to detect the bacterial causes of TB and leprosy (mycobacteria) as this kind of bacteria cannot be gram stained.

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

What is a pathogen?

A

A bacterium, virus or other microoganism that can cause disease.

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

Why are RNA viruses more likely to mutate?

A

Because RNA is less stable than DNA

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

How does an envelope affect the survival of a virus?

A

Viruses with envelopes are more easily sterilised as when holes are punched in the envelope the virus cannot survive.

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

What are the three ways by which a virus can replicate?

A

RNA viruses use reverse transcriptase, DNA viruses use cell machinery or other viruses carry their own replication enzymes.

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

Name three DNA enveloped viruses and describe the conditions they cause.

A

Hepatitis B causes inflamed liver
Herpes causes oral/genital herpes
Smallpox virus causes smallpox

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

Name one DNA non-enveloped viruses and describe the condition it causes.

A

HPV virus causes Warts & cervical cancer

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Name four RNA enveloped viruses and describe the conditions they cause.

A

HIV causes AIDS
Rubella causes Congenital Rubella Syndrome
Rotavirus caused Diarrhoea
Corona virus causes SARS

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Name two RNA non-enveloped viruses and describe the conditions they cause.

A

Polio causes inflammation of the spinal cord

Hepatitis A causes Liver disease.

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

List two gram positive cocci

A

Staphylococcus

Streptococcus

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

What do the following types of bacteria look like? a) Staphylococci b) Bacilli c) Streptococci d) Diplococci

A

a) Clusters of circular bacteria
b) Rod shaped bacteria
c) Chains of circular bacteria
d) Pairs of circular bacteria

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

Name one gram negative cocci

A

Neisseria

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

Name one Gram positive bacilli

A

Clostridium

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Name six Gram negative bacilli

A 
Escherichia
Salmonella
Helicobacter
Pseudomonas
Leigonella
Bacteroides
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Name two types of bacteria that cannot be identified with a gram stain

A

Mycobacterium and Chlamydia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

What does staphylococcus aureus cause?

A

Abscesses, toxic shock syndrome, food poisoning

27
Q

What does streptococus pyogenes cause?

A

Necrotising fasciitis

28
Q

What does Group B streptococci cause?

A

Neonatal sepsis and meningitis

29
Q

What does streptococcus pneumoniae cause?

A

Pneumonia, meningitis, sepsis, endocarditis

30
Q

What does clostridium perfingens cause?

A

Gas gangrene

31
Q

What does clostridium difficile cause?

A

Antibiotic associated diarrhoea (C-Dif)

32
Q

What does Neisseria mengitidis cause?

A

Septicaemia and meningitis

33
Q

What does Neisseria gonorrhoea cause?

A

Gonorrhoea

34
Q

What does Escherichia coli cause?

A

E.coli (watery diarrhoea, renal failure)

35
Q

What does samonella spp. cause?

A

Gastroenteritis

36
Q

What does Shigella cause?

A

Dysentery, bloody diarrhoea

37
Q

What does pseudomonas aeruginosa cause?

A

Generalised inflammation, sepsis

38
Q

What does Legionella spp. cause?

A

Legionnaire’s disease, acute influenza, pneumonia

39
Q

What does Helicobacter pylori cause?

A

peptic ulcers, especially duodenal ulcers

40
Q

What does Bacteriodes spp cause?

A

Abesses, lesions

41
Q

What does chlamydia spp. cause?

A

Chlamydia

42
Q

What does mycobacterium tuberculosis cause?

A

Tuberculosis

43
Q

What does Mycobacterium leprae cause?

A

Leprosy

44
Q

Name 4 Beta-Lactam antibiotics and mention which part of the bacteria they target.

A

Penicillin, Amoxicillin, Flucloxacillin, Cephalexin. They target the cell wall.

45
Q

How does penicillin work?

A

Non competitive inhibition of transpeptidase. It inhibits peptidoglycan formation of cross links. It mainly acts on gram positive bacteria due to their thick peptidoglycan cell wall.

46
Q

How do bacteria become resistant to penicillin?

A

They begin to synthesise penicillinase which destroys the beta-lactam ring and stops it interfering with synthesis of transpeptidase.

47
Q

How can antibiotic resistance be inherited (3 ways)?

A

Horizontal gene transfer
Vertical gene transfer
Transduction in vesicle

48
Q

How do rifamycins work?

A

It targets RNA polymerase and inhibits it via steric occlusion

49
Q

What are rifamycins used for?

A

TB, Hansens disease, multiresistant antibiotic strains

50
Q

What is penicillin used for?

A

Fighting bacterial infection and preventing infection in people with low immune system.

51
Q

Name two antifolates

A

Methotrexate
Metronidazole
Trimethoprim

52
Q

What is tetracycline?

A

An antibiotic that binds to the 30s RNA subunits in the bacterium and blocks it. This stops protein synthesis occurring.

53
Q

When is tetracycline used?

A

To treat chlamydia, leptosporosis, lymes diosease and helicobacteria

54
Q

How do bacteria become resistant to tetracycline?

A

They enzymatically inactivate the tetracycline and stop it binding.

55
Q

How does methotrexate work?

A

It inhibits the DHFR enzyme so there is a reduced amount of FH4. This results in a lower amount of purines being produced so a lower amount of DNA, hence inhibiting replication.

56
Q

How do cells acquire resistance to methotrexate?

A

They detect decreased enzyme activity and upregulate this by gene amplification, hence forming more DHFR enzyme.

57
Q

Name 3 different habitats that may be occupied by microbes

A

Air
Soil
Bodily Fluids

58
Q

What does ‘Reservoir’ mean in the context of infection?

A

Any habitat in which an infectious agent lives or multiplies

59
Q

What does ‘source’ mean in terms of infection?

A

A readily available form of infection agent.

60
Q

What does ‘mode of transmission’ mean? Name three.

A

The way in which the infectious agent is passed from one reservoir to another. e.g. ingestion, inhalation, physical contact, inoculation, sexual contact

61
Q

What does ‘carriage’ mean?

A

The passage taken by the microorganism e.g. throat

62
Q

What does “normal flora” mean?

A

The normal, healthy bacteria we find in our bodies

63
Q

What does “commensal” mean?

A

A symbiotic relationship where the microbe derives benefit but the host is unaffected.

ESA 1 Revision (14 decks)

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