Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

MICRB 106 - Exam 4 > Antimicrobial Drugs > Flashcards

Antimicrobial Drugs Flashcards

(72 cards)

Start Studying
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
______ polymerize NAG - NAM subunits
Transglycosylases
26
______ cross-link short peptide chains of neighboring NAM molecules
Transpeptidases
27
What are beta-lactams?
Antimicrobials that prevent cross-linking of NAM subunits
28
What term is used to refer to beta-lactam functional portions?
Beta-lactam rings
29
Name 2 examples of beta-lactams
- Penicillin - Cephalosporin
30
How do beta-lactams specifically inhibit cell wall synthesis?
By irreversibly binding to transpeptidases
31
What occurs in the absence of correctly formed peptidoglycan in the inhibition of cell wall synthesis?
Growing bacterial cells are less resistant to the effects of osmotic pressure
32
What ultimate effect do beta-lactams have upon the bacterial cell - how do they kill?
They create semi-synthetic derivatives
33
Name an example of a semisynthetic derivative of natural penicillin
MRSA
34
Name 3 advantages of semisynthetic penicillins over natural penicillin
- More stable - More readily absorbed - Less susceptible to deactivation
35
What cellular target or mechanism of action does the drug vancomycin affect?
Alanine-alanine cross-bridges
36
Vancomycin inhibits ______
Biosynthesis
37
What cellular target or mechanism of action does the drug bacitracin affect?
Prevents cell wall formation
38
How does bacitracin specifically act?
Blocks the transport of NAG and NAM across the cytoplasmic membrane
39
What is bactoprenol?
Membrane localized carrier molecule
40
What effect does bacitracin have upon the bacterial cell - how does it kill?
Causes cell lysis due to osmotic pressure
41
Describe how beta-lactams, vancomycin, and bacitracin have NO effect on existing peptidoglycan
They are effective only on growing, reproducing cells - dormant cells are unaffected
42
How do aminoglycosides work?
Change the shape of the 30S subunit
43
Aminoglycosides prevent ______
Reading of mRNA codons
44
Name an example of an aminoglycoside
Streptomycin
45
How do tetracyclines work?
Block the tRNA docking site (A site)
46
Tetracyclines prevent _______
Amino acid binding
47
How does chloramphenicol work?
Blocks the enzymatic site of the 50S subunit
48
Chloramphenicol prevents ______
Peptide bond formation
49
How do macrolides work?
Bind to a different portion of the 50S subunit
50
Macrolides prevent ______
Translocation
51
Name an example of a macrolide
Erythromycin
52
What is translocation?
Movement of the ribosome from one codon to the next
53
How do antifungal polyenes work?
Disrupt the cytoplasmic membrane
54
What is ergosterol?
A lipid in fungal membranes
55
Name the 2 different polyenes
- Nystatin - Amphotericin B
56
Nystatin and Amphotericin B are ______ because they attach to ergosterol
Fungicidal
57
______ is structurally similar to ergosterol
Cholesterol
58
How do sulfonamides or ‘sulfa drugs’ act as antimetabolite drugs?
They are structural analogs of PABA
59
What is the function of PABA in normal bacterial biochemistry?
Synthesis of nucleotides required for DNA and RNA synthesis
60
PABA is enzymatically converted into ______
Dihydrofolic acid
61
Dihydrofolic acid is enzymatically converted into ______
Tetrahydrofolic acid (THF)
62
How does sulfanilamide specifically inhibit folic acid synthesis in bacteria? (2)
- Sulfanilamides compete with PABA for the active site - Folic acid enzyme is deactivated
63
Why are sulfa drugs safe for humans to use? (2)
- Humans do NOT synthesize THF from PABA - Human metabolism is unaffected by sulfanilamides
64
The antimetabolic agent trimethoprim interferes with ______
Nucleic acid synthesis
65
______ distort the shapes of the nucleic acid molecules
Nucleotide analogs
66
Viruses are more likely than host cells to incorporate ______
Nucleotide analogs
67
What is the specific target of the synthetic drugs called quinones or fluoroquinolones?
Prokaryotic DNA
68
What process do quinones or fluoroquinolones interfere with?
DNA gyrase
69
What is the role of DNA gyrase?
Coiling and uncoiling of replicating DNA
70
What is microbial antagonism?
The competition among microbes for nutrients and space
71
Describe an example of microbial antagonism in normal physiology
Women taking strep throat antibiotics can develop a yeast infection from Candida albicans
72
What are beta-lactamases or ‘penicillinases’?
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.
© 2025 Bold Learning Solutions. Terms and Conditions