30s Protein Synthesis Inhibitors Med Chem Flashcards
Which of these drug classes binds to 30s subunits? (select all)
A. Tetracyclines
B. Glycyclines
C. Lincosamide
D. Macrolides
E. Aminoglycosides
A, B, E
What site does tetracycline bind to on the 30s subunit?
A. A-Site
B. P-Site
C. E-Site
D. All sites
A
The yellow boxes represent the A, P and E sites on a 30s subunit. The yellow box to the right is the A site. Middle yellow box is the P-site and the left yellow box is the E site
The structure on the left is the common moeity seen in tetracyclines and is known as a _____.
A. Tetrabenzyl
B. Quadrobenzyl
C. Napthacene
D. Tribenzyl
C
What is the mechanism of action of Tetracycline medications?
A. Binds to the 50s subunits and prevents protein synthesis
B. Binds to the A-site on 30s subunits and prevents protein synthesis (prevents aminoacyl tRNA binding to mRNA)
C. Binds to the P-site on 30s subunits and prevents the tRNA from moving
D. none of the above
B
Tetracyclines are ____
A. Bacteriocidal
B. Bacteriostatic
B
Which of the following statements is true regarding Tetracycline medications? (select all)
A. Narrow-spectrum
B. Broad-spectrum (gram positive and negative)
C. Used to treat Lyme disease
D. Used in the management of acne
B, C, D
What are the types of bacterial resistances against tetracycline antibiotics?
A. Increased efflux of medication (tetK efflux pump)
B. Altered target (tetM). Ribosomal protection portein will displace tetracyclines from binding to their active site (A-site)
C. Cross resistance
D. Enzymatic inactivation (tetX)
E. All of the above
E
Cross-resistance is when resistance has been developed to one tetracycline and as a result will be developed towards another tetracycline as well.. For example if bacteria become resistant to doxycycline then it will also be resistant to minocycline and tetracycline.
Ribosomal protection proteins will prevent the tetracyclines from binding to the A-site on the 30s subunit.
The red boxed structure of the tetracycline represents the ____ bridge and the blue boxed structure of the tetracycline represents the _____ bridge.
A. Southern, Northern
B. Northern , Southern
B
T/F The northern bridge of the tetracycline antibiotics is where the chemical structures will differ between tetracycline antibiotics.
T
T/F The southern bridge of the tetracycline antibiotics is where the drug will bind to the 30s subunits. The southern bridge will also be different between each tetracycline antibioitc.
F
It is the site that binds to the 30s subunits but the southern bridge will NOT change between tetracycline antibiotics
When looking at the general structure of tetracycline antibiotics, Doxycycline will have a substituted ___ group at the R3 position.
A. NH2
B. OH
C. CH3
D. H
C
When looking at the general structure of tetracycline antibiotics, Minocycline will have a ___ group on its R3 and R4 positions
A. NH2
B. H
C. CH3
D. None of the above
B.
Which of the following are true regarding the Physico-Chemical properties of tetracyclines?
A. Conjugated double bonds give tetracycline its yellow color
B. It is amphoteric (Acts as an acid or a base)
C. Contains dimethyl-amino group that is important for activity
D. All of the above
D
The circled structure in blue is the dimethyl amino group
All of the following are cautions that a patient should be counseled on when giving tetracyclines EXCEPT:
A. Do not take tetracyclines with milk or any other polyvalent metal ions unless its 1 hour before or 2 hours after taking Tetracycline
B. May be given in children that are under 12 years old
C. Can cause Phototoxicity (rash)
D. Can cause yellowing of teeth that have yet to grow out.
B
A: Polyvalent metal ions such as calcium can chelate (bind) to tetracycline and make the tetracycline useless as a result
B: cannot give to children under 12 because they haven’t yet developed their adult teeth and the medication can cause them to yellow
Answer question based on the picture provided
B. II
Need to go over instabilities in the power point
The structure of the glycycline antibiotic (Tigecycline) is shown here. All of the following statements are true EXCEPT:
A. It is known as a t-butylglyclamido substitution.
B. Helps glycylcline avoid tetracycline resistance by enhancing its affinity for the binding site on 30s subunits.
C. Helps glycycline avoid efflux from bacterial cells due to the steric hindrance the bulky group provides
D. Helps glycycline avoid tetracycline resistance by enhancing its affinity for the binding site on 50s subunits.
D
