12. Microbial Metabolism

In the electron transport chain, the final electron acceptor is:

a) H₂O.

b) CO₂.

c) H₂O.

d) O₂.

e) NAD⁺.

Which of the following events takes place in the electron transport chain?

a) The breakdown of glucose into six carbon dioxide molecules.

b) The breakdown of NADH and FADH₂ to carbon dioxide.

c) Harnessing energy from high-energy electrons derived from glycolysis, pyruvate oxidation, and the Krebs cycle.

d) Substrate-level phosphorylation.

TRUE or FALSE:Electron transport in eukaryotes occurs in the inner mitochondrial membrane.

DRAW IT What nutritional type is a colorless microbe that uses the Calvin-Benson cycle, uses H₂ as the electron donor to its ETC, and uses elemental S as the final electron acceptor in the ETC?

Complete the table.

Use the following diagrams (a), (b), and (c) for question 1.

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Name pathways diagrammed in parts (a), (b), and (c) of the figure.

a. Show where glycerol is catabolized and where fatty acids are catabolized.

b. Show where glutamic acid (an amino acid) is catabolized:

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c. Show how these pathways are related.

d. Where is ATP required in pathways (a) and (b)?

e. Where is CO₂ released in pathways (b) and (c)?

f. Show where a long-chain hydrocarbon such as petroleum is catabolized.

g. Where is NADH (or FADH₂ or NADPH) used and produced in these pathways?

h. Identify four places where anabolic and catabolic pathways are integrated.