GED Science Practice

What class of drugs consists of synthetic organic compounds capable of inhibiting the growth of bacteria that require PABA?

1. Symbiosis

2. Streptomycin

3. Sublimation

4. Sulfa drug

The correct answer is: Sulfa drug

The class of drugs that consists of synthetic organic compounds capable of inhibiting the growth of bacteria requiring para-aminobenzoic acid (PABA) is known as sulfa drugs. These drugs work by mimicking PABA, which is a substrate for the bacterial enzyme involved in the synthesis of folic acid. By substituting for PABA in the bacterial metabolic pathway, sulfa drugs effectively inhibit the production of folic acid, a critical nutrient that bacteria need for growth and reproduction. This mechanism makes sulfa drugs effective antibiotics against certain bacterial infections. Understanding this action is fundamental to pharmacology and microbiology, as it demonstrates how synthetic compounds can be designed to target specific biological processes in microorganisms. The other choices listed—symbiosis, streptomycin, and sublimation—do not pertain to synthetic drugs that specifically inhibit bacterial growth through the mechanism related to PABA. Symbiosis refers to a biological relationship between two species, streptomycin is an antibiotic with a different mechanism of action, and sublimation is a phase transition of materials, completely unrelated to antibiotic activity. Therefore, identifying sulfa drugs as the correct answer is crucial in studying bacterial resistance and antibiotic treatment options.