Brainscape's Knowledge GenomeTM

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


See full index

PHAR20400 > INHIBITORS OF PROTEIN SYNTHESIS I > Flashcards

INHIBITORS OF PROTEIN SYNTHESIS I Flashcards

1
Q

How much does the ribosome make up of the dry weight of bacterial cells?

A

30%

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

How many proteins and RNA strands make up a ribosome?

A

Around 55 proteins and 3 strands of RNA

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

Why are ribosomes a good antibacterial target?

A

Protein synthesis must continue even when cells are dormant or slow-growing (e.g. in biofilm or a mycobacterium), so targeting the ribosome, will target all bacterial cells

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

How much energy can protein synthesis take up of a bacterial cell?

A

Up to 40%

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

What is tetracycline biosynthesized from?

A

From acetate, by species of Streptomyces

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

What components does tetracycline bind?

A
  • Nucleic acid
  • Proteins
  • Ribosomes (only this bind inhibits cell function)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What’s the mechanism of action of tetracycline?

A

Tetracycline prevents amino-acyl tRNA from binding to the elongation factor TU on the 30S ribosomal subunits = prevents the protein chain from growing

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

How are bacteria resistant to tetracycline?

A
  • Cell membrane modifications (changes to permeability to drug and use of efflux pumps)
  • mutations in the S10 ribosomal protein also cause resistance (prevent binding)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Why are tetracyclines contraindicated in children?

A

They stain growing tooth enamel

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

What’s chlortetracycline used for?

A

Conjuctivitis in cats

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

What’s oxytetracycline used to treat and why is it used?

A

Acne and oxytetracycline is used because it’s well absorbed

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

What’s demeclocycline used for? (2)

A

Treats Lyme disease and SIADH (syndrome of inappropriate antidiuretic hormone)

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

What’s doxycycline used for? (2)

A

It is an antibacterial and used for malaria prophylaxis

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

What’s lymecycline used for and why is it used?

A
  • Used to treat severe acne
  • Lymecycline is 5000x more soluble than tetracycline + well-tolerated
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What’s minocycline used for and why is it able to treat this disease?

A
  • Treats Neisseria meningtidis.
  • It’s a broader spectrum AB than other tetracyclines
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What are some examples of aminoglycoside antibiotics? (4)

A
  1. Gentamycin
  2. Streptomycin
  3. Kanamycin
  4. Neomycin
17
Q

What’s the chemical structure of aminoglycoside antibiotics?

A

Aminoglycoside contain several sugar rings and min. of one amino acids

18
Q

What’s the mechanism of action of aminoglycosides?

A
  • Binds to 30S ribosomal subunits, specifically 16S RNA
  • Binding of Aminoacyl-tRNA to the A site is inhibited – no peptide bonds formed
  • Genetic code is misread
19
Q

What type of gram bacteria is aminoglycosides most effective against?

A

Very active against gram -ve bacteria

Disrupts the cell wall

20
Q

Why are aminoglycoside antibiotics not used that often? (3)

A
  • Has to be given by intramuscular injection because they are hydrophilic
  • Has a very narrow therapeutic index - toxic
  • Show nephotoxicity
21
Q

Why is Gentamicin different from other aminoglycoside antibiotics?

A

Gentamicin is derived from Micromonospora, not Streptomyces (like other aminoglycosides)

  • Gentamicin is also the most successful of the aminoglycosides
22
Q

How does tobramycin work?

A

Binds to 30S and 50S ribosomal subunits, preventing them combining.

23
Q

What is tobramycin used to treat and how is it used?

A
  • For Pseudomonas aeruginosa infections
  • Inhaled by cystic fibrosis patients
24
Q

What is amikacin derived from and what’s it used to treat?

A
  • Kanamycin
  • Treats serious, hospital-acquired Gram negative infections
25
Q

What is paramomycin used for?

A

Treats leishmaniasis (cutaneous and visceral)

26
Q

What are oxazolidinones and what are they used as?

A
  • Synthetic compounds
  • Used as monoamine oxidase inhibitors and antibacterials
27
Q
  • What’s an example of an oxazolidinone?
  • What’s it used for?
  • What type of bacteria is oxazolidinone active against?
A
  • Linezolid
  • Active against multiply resistant bacteria including MRSA
  • Used for gram +ve hospital infections e.g S. aureus
28
Q

What’s the mechanism of Linezolid?

A

Binds to 50S ribosomal subunit (23S RNA) and prevents the 30S subunit joining it.

29
Q

Linezolid is toxic to mitochondria. True or false?

A

True

30
Q

Name the structure

A

Tetracycline

31
Q

Name the structure

A

Oxazolidinones

32
Q

Name the structure

A

Aminoglycosides

PHAR20400 (20 decks)

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