Skip to main content
Ch. 10 - Controlling Microbial Growth in the Body: Antimicrobial Drugs
Bauman - Microbiology with Diseases by Taxonomy 6th Edition
Bauman6th EditionMicrobiology with Diseases by TaxonomyISBN: 9780134832302Non è quello che usi tu?Cambia libro di testo
Capitolo 10, Problema 4

Which of the following statements is relevant in explaining why sulfonamides are effective?
a. Sulfonamides attach to sterol lipids in the pathogen, disrupt the membranes, and lyse the cells.
b. Sulfonamides prevent the incorporation of amino acids into polypeptide chains.
c. Humans and microbes use PABA differently in their metabolism.
d. Sulfonamides inhibit DNA replication in both pathogens and human cells.

Guida verificata passo dopo passo
1
Understand the mechanism of action of sulfonamides: Sulfonamides are antimicrobial agents that interfere with the synthesis of folic acid in bacteria.
Recall that folic acid is essential for the synthesis of nucleotides, which are the building blocks of DNA and RNA, and that bacteria synthesize folic acid from para-aminobenzoic acid (PABA).
Recognize that sulfonamides are structural analogs of PABA and competitively inhibit the enzyme dihydropteroate synthase, which incorporates PABA into folic acid synthesis in bacteria.
Note that humans do not synthesize folic acid and instead obtain it from their diet, so the metabolic pathway involving PABA is different in humans compared to bacteria.
Conclude that the relevant explanation for sulfonamide effectiveness is that humans and microbes use PABA differently in their metabolism, making option (c) the correct choice.

Risposta video verificata per un problema simile:

Questa soluzione video è stata consigliata dai nostri tutor come utile per risolvere questo problema.
Durata del video:
3m

Concetti chiave

Ecco i concetti essenziali che devi comprendere per rispondere correttamente alla domanda.

Mechanism of Action of Sulfonamides

Sulfonamides are antimicrobial agents that inhibit the synthesis of folic acid in bacteria by acting as competitive inhibitors of para-aminobenzoic acid (PABA). This disruption prevents the production of nucleotides necessary for DNA and RNA synthesis, leading to bacterial growth inhibition.
Video consigliato:
01:59
Introduction to Avoiding Host Defense Mechanisms

Role of PABA in Microbial Metabolism

PABA is a precursor molecule used by bacteria to synthesize folic acid, an essential vitamin for nucleic acid production. Humans do not synthesize folic acid and instead obtain it from their diet, making PABA metabolism a selective target for antibiotics like sulfonamides.
Video consigliato:
02:17
Introduction to Metabolism

Selective Toxicity in Antimicrobial Therapy

Selective toxicity refers to the ability of a drug to target microbial cells without harming human cells. Sulfonamides exploit differences in folic acid metabolism between microbes and humans, allowing them to inhibit bacterial growth while minimizing effects on human cells.
Video consigliato:
03:27
Selective Media