Exam 13: Metabolic Diversity of Microorganisms

Explain why the discovery of iron-oxidizing phototrophs has important implications for both understanding the evolution of photosynthesis and explaining the large deposits of ferric iron (Fe³⁺)found in ancient sediments on Earth.

How is ATP made by an acetogen during CO₂ fixation?

Chemolithotrophs that obtain electrons from donors such as sulfide use the same electron transport chains to obtain energy as chemoorganotrophs.

Carotenoids are hydrophobic accessory pigments and vary widely in the color they can absorb.

In contrast to chlorophylls,carotenoids function

In most cases,the final product of sulfur oxidation is

Photosystem I is responsible for splitting a water molecule in the first step of oxygenic electron flow.