Antibacterial Agents: Protein Synthesis Inhibitors

Where are ribosomes located in mammalian cells?

In the endoplasmic reticulum (correct)
In the cytoplasm
In the mitochondria
In the nucleus

What is the process by which cells make proteins?

Protein synthesis (correct)
Transcription
Translation
DNA replication

What is the difference between mammalian and bacterial ribosomes?

Location
Shape
Size
Subunit composition (correct)

What is the first step in protein synthesis?

Transcription (B) Signup and view all the answers

What is the end product of protein synthesis?

Finished protein (D) Signup and view all the answers

Where does protein synthesis occur in bacterial cells?

In the cytoplasm (D) Signup and view all the answers

What is the role of initiation in protein synthesis?

To start the translation process (C) Signup and view all the answers

What is the purpose of protein synthesis inhibitors?

To selectively target bacterial protein synthesis (C) Signup and view all the answers

What is the mechanism of action of aminoglycosides?

Binds to 30s subunit, causing misreading of mRNA (B) Signup and view all the answers

What is the significance of the peak/MIC ratio in aminoglycoside therapy?

It should be at least 10:1 for effective bactericidal activity (D) Signup and view all the answers

Why do aminoglycosides have minimal action against anaerobes?

Because they require oxygen-dependent active transport (A) Signup and view all the answers

How are aminoglycosides excreted from the body?

Almost entirely through glomerular filtration (A) Signup and view all the answers

What is the half-life of aminoglycosides in patients with normal renal function?

Around 2-3 hours (B) Signup and view all the answers

What is the mechanism of resistance to aminoglycosides?

All of the above (D) Signup and view all the answers

What is the preferred treatment for plague and tularaemia?

Aminoglycosides (D) Signup and view all the answers

What is the significance of the volume of distribution of aminoglycosides?

It approaches total body volume (B) Signup and view all the answers

What is the primary function of the small and large subunits of the ribosome during translation?

To bind to the mRNA and initiate translation (A) Signup and view all the answers

What is the role of the stop codon during translation?

To bind a release factor and break apart the complex (A) Signup and view all the answers

What is the primary difference between antibiotics and antimicrobials?

Antibiotics treat only bacterial infections, while antimicrobials treat a broader range of infections (D) Signup and view all the answers

What is the key difference between bacteriostatic and bactericidal antimicrobials?

Bacteriostatic antimicrobials inhibit the growth of bacteria, while bactericidal antimicrobials kill bacteria (A) Signup and view all the answers

What is the focus of pharmacokinetics?

How a drug is processed by the body (A) Signup and view all the answers

What is the primary characteristic of aminoglycosides?

They have a complex chemical structure with three hexagonal rings (A) Signup and view all the answers

What is the MIC (minimum inhibitory concentration) of an antimicrobial?

The lowest concentration of the antimicrobial that results in inhibition of detectable growth of the organism (C) Signup and view all the answers

What is the relationship between gentamicin, amikacin, and tobramycin?

They are all aminoglycosides with similar anti-microbial activity and pharmacokinetics (B) Signup and view all the answers

What is the primary mechanism of action of tigecycline in bacterial cells?

Inhibiting protein synthesis by blocking the entry of tRNA molecules (A) Signup and view all the answers

What is the main reason for the decreased absorption of tetracyclines in the presence of divalent and trivalent cations?

The cations form a complex with the tetracycline, reducing its bioavailability (B) Signup and view all the answers

What is the primary mechanism of resistance to tetracyclines in bacteria?

Increased efflux of the drug from the bacterial cell (B) Signup and view all the answers

What is the primary indication for the use of doxycycline in respiratory tract infections?

Atypical pneumonia caused by Mycoplasma or Chlamydia (B) Signup and view all the answers

What is the unique feature of demeclocycline compared to other tetracyclines?

It renders renal tubular cells unresponsive to ADH, treating SIADH (C) Signup and view all the answers

What is the primary route of excretion for tetracyclines?

Bile and kidney (A) Signup and view all the answers

What is the primary mechanism of action of tetracyclines against Chlamydia?

Inhibiting protein synthesis by binding to the 30s ribosomal subunit (D) Signup and view all the answers

What is the primary reason for the use of tetracyclines in the treatment of acne?

Their ability to inhibit the growth of Propionibacterium acnes (A) Signup and view all the answers

Which of the following bacteria is not susceptible to aminoglycosides?

Staphylococcus aureus (D) Signup and view all the answers

What is the primary mechanism of action of aminoglycosides?

Inhibition of protein synthesis by competing with tRNA for the A site on the ribosome (B) Signup and view all the answers

Which aminoglycoside has the widest spectrum of activity?

Amikacin (B) Signup and view all the answers

What is the primary side effect of aminoglycosides on the kidney?

Proximal tubular necrosis (B) Signup and view all the answers

What is the primary side effect of aminoglycosides on the ear?

Cochlear toxicity (D) Signup and view all the answers

What is the primary indication for using tobramycin over gentamicin?

Pseudomonas infections (C) Signup and view all the answers

What is the primary mechanism of action of tetracyclines?

Inhibition of protein synthesis by binding to the 30S ribosomal subunit (B) Signup and view all the answers

Which of the following is a common side effect of aminoglycosides that may go unrecognized?

Vestibular toxicity (B) Signup and view all the answers