A microbiologist studies purple sulfur bacteria in a volcanic spring. Which molecule do these organisms use as an electron donor for photosynthesis?
Q1. A microbiologist studies purple sulfur bacteria in a volcanic spring. Which molecule do these organisms use as an electron donor for photosynthesis?
Answer: Hydrogen sulfide
Explanation: Sulfur bacteria use H2S as a reducing agent, releasing sulfur instead of oxygen. H2O is wrong because they are specifically non-oxygenic.