Brainscape's Knowledge GenomeTM

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


See full index

MICRB 106 - Exam 4 > Antimicrobial Drugs > Flashcards

Antimicrobial Drugs Flashcards

1
Q

Define drugs

A

Chemicals that affect physiology in any manner

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

Define chemotherapeutic agents

A

Drugs that act against diseases

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

Define antimicrobials

A

Drugs used for treating infections

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

What is chemotherapy?

A

The use of chemicals to selectively kill pathogens while having little or no effect on the patient

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

Which microbiologist is generally credited with proposing the term chemotherapy?

A

Paul Ehrlich

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

What was the name of the chemotherapeutic agent that Paul Ehrilch developed?

A

Magic bullet - arsenic containing compound

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

What disease did the ‘magic bullet’ treat?

A

Syphilis (salvarsan)

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

Which scientist is credited with reporting the antimicrobial action of penicillin secreted from Penicillium mold?

A

Alexander Fleming

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

Explain why Salvarsan and penicillin were not the first antimicrobial drugs to be widely used (2)

A
  • Arsenic compounds are toxic to humans
  • Penicillin was not made available in large enough quantities until the 1940s
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What was the name of the first practical antimicrobial used to treat a wide array of bacterial infections?

A

Sulfanilamide

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

Name the bacteriologist that discovered the sulfanilamide

A

Gerhard Domagk

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

Which scientist focused on soil-dwelling bacteria?

A

Selman Waksman

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

What was the most notable species of soil-dwelling bacteria discovered by Selman Waksman?

A

Streptomyces

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

Define antibiotic

A

Antimicrobial agents that are produced naturally by an organism

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

Which scientist originally coined the term “antibiotic”?

A

Selman Waksman

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

Chemically altered antibiotics are known as ______

A

Semi-synthetics

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

Antimicrobials that are completely synthesized in a laboratory are known as ______

A

Synthetics

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

Explain the concept of selective toxicity

A

An effective microbial agent must be more toxic to a pathogen than to a host

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

How is selective toxicity possible?

A

Differences in the structure between the pathogen and host

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

Why are there far more antibacterial drugs than any other kinds of antimicrobials?

A

Greatest number and diversity

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

Why are antiviral drugs especially limited?

A

They are likely toxic to the host

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

Name 5 different targets or mechanisms of action by which antimicrobial drugs can be categorized

A
  • Cell wall synthesis
  • Cytoplasmic synthesis
  • DNA / RNA synthesis
  • Protein synthesis
  • Metabolism
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

How are the sugars N-acetylglucosamine (NAG) and N-acetylmuramic acid (NAM) positioned relative to each other?

A

Cross-linked by short peptide chains extending between NAM subunits

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

What is the fundamental ‘subunit’ or ‘building block’ of peptidoglycan?

A

Amino acid sugars and tetrapeptides

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

______ polymerize NAG - NAM subunits

A

Transglycosylases

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

______ cross-link short peptide chains of neighboring NAM molecules

A

Transpeptidases

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

What are beta-lactams?

A

Antimicrobials that prevent cross-linking of NAM subunits

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

What term is used to refer to beta-lactam functional portions?

A

Beta-lactam rings

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

Name 2 examples of beta-lactams

A
  • Penicillin
  • Cephalosporin
30
Q

How do beta-lactams specifically inhibit cell wall synthesis?

A

By irreversibly binding to transpeptidases

31
Q

What occurs in the absence of correctly formed peptidoglycan in the inhibition of cell wall synthesis?

A

Growing bacterial cells are less resistant to the effects of osmotic pressure

32
Q

What ultimate effect do beta-lactams have upon the bacterial cell - how do they kill?

A

They create semi-synthetic derivatives

33
Q

Name an example of a semisynthetic derivative of natural penicillin

A

MRSA

34
Q

Name 3 advantages of semisynthetic penicillins over natural penicillin

A
  • More stable
  • More readily absorbed
  • Less susceptible to deactivation
35
Q

What cellular target or mechanism of action does the drug vancomycin affect?

A

Alanine-alanine cross-bridges

36
Q

Vancomycin inhibits ______

A

Biosynthesis

37
Q

What cellular target or mechanism of action does the drug bacitracin affect?

A

Prevents cell wall formation

38
Q

How does bacitracin specifically act?

A

Blocks the transport of NAG and NAM across the cytoplasmic membrane

39
Q

What is bactoprenol?

A

Membrane localized carrier molecule

40
Q

What effect does bacitracin have upon the bacterial cell - how does it kill?

A

Causes cell lysis due to osmotic pressure

41
Q

Describe how beta-lactams, vancomycin, and bacitracin have NO effect on existing peptidoglycan

A

They are effective only on growing, reproducing cells - dormant cells are unaffected

42
Q

How do aminoglycosides work?

A

Change the shape of the 30S subunit

43
Q

Aminoglycosides prevent ______

A

Reading of mRNA codons

44
Q

Name an example of an aminoglycoside

A

Streptomycin

45
Q

How do tetracyclines work?

A

Block the tRNA docking site (A site)

46
Q

Tetracyclines prevent _______

A

Amino acid binding

47
Q

How does chloramphenicol work?

A

Blocks the enzymatic site of the 50S subunit

48
Q

Chloramphenicol prevents ______

A

Peptide bond formation

49
Q

How do macrolides work?

A

Bind to a different portion of the 50S subunit

50
Q

Macrolides prevent ______

A

Translocation

51
Q

Name an example of a macrolide

A

Erythromycin

52
Q

What is translocation?

A

Movement of the ribosome from one codon to the next

53
Q

How do antifungal polyenes work?

A

Disrupt the cytoplasmic membrane

54
Q

What is ergosterol?

A

A lipid in fungal membranes

55
Q

Name the 2 different polyenes

A
  • Nystatin
  • Amphotericin B
56
Q

Nystatin and Amphotericin B are ______ because they attach to ergosterol

A

Fungicidal

57
Q

______ is structurally similar to ergosterol

A

Cholesterol

58
Q

How do sulfonamides or ‘sulfa drugs’ act as antimetabolite drugs?

A

They are structural analogs of PABA

59
Q

What is the function of PABA in normal bacterial biochemistry?

A

Synthesis of nucleotides required for DNA and RNA synthesis

60
Q

PABA is enzymatically converted into ______

A

Dihydrofolic acid

61
Q

Dihydrofolic acid is enzymatically converted into ______

A

Tetrahydrofolic acid (THF)

62
Q

How does sulfanilamide specifically inhibit folic acid synthesis in bacteria? (2)

A
  • Sulfanilamides compete with PABA for the active site
  • Folic acid enzyme is deactivated
63
Q

Why are sulfa drugs safe for humans to use? (2)

A
  • Humans do NOT synthesize THF from PABA
  • Human metabolism is unaffected by sulfanilamides
64
Q

The antimetabolic agent trimethoprim interferes with ______

A

Nucleic acid synthesis

65
Q

______ distort the shapes of the nucleic acid molecules

A

Nucleotide analogs

66
Q

Viruses are more likely than host cells to incorporate ______

A

Nucleotide analogs

67
Q

What is the specific target of the synthetic drugs called quinones or fluoroquinolones?

A

Prokaryotic DNA

68
Q

What process do quinones or fluoroquinolones interfere with?

A

DNA gyrase

69
Q

What is the role of DNA gyrase?

A

Coiling and uncoiling of replicating DNA

70
Q

What is microbial antagonism?

A

The competition among microbes for nutrients and space

71
Q

Describe an example of microbial antagonism in normal physiology

A

Women taking strep throat antibiotics can develop a yeast infection from Candida albicans

72
Q

What are beta-lactamases or ‘penicillinases’?

A

Enzymes that break the beta-lactam rings of penicillin

MICRB 106 - Exam 4 (4 decks)

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