Microbiology: Microbial Metabolism Flashcards
7 cards from real AP practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Microbiology: Microbial Metabolism flashcards as text
Which enzyme complex is responsible for pumping protons across the inner mitochondrial or bacterial membrane during electron transport?
Answer: NADH dehydrogenase (Complex I)
NADH dehydrogenase (Complex I) oxidizes NADH and pumps protons across the membrane, contributing to the proton motive force.
What is the net ATP yield from substrate-level phosphorylation during glycolysis alone (per glucose)?
Answer: 2 ATP
Glycolysis produces 4 ATP but consumes 2 ATP for a net yield of 2 ATP via substrate-level phosphorylation.
A bacterium living in a deep-sea hydrothermal vent uses H2S as an electron donor to fix CO2. This organism is best classified as a:
Answer: Chemoautotroph (lithotroph)
Chemoautotrophs (lithotrophs) obtain energy from inorganic compounds like H2S and use CO2 as a carbon source.
During the citric acid cycle, how many NADH molecules are produced per acetyl-CoA entering?
Answer: 3
Three NADH molecules are generated per acetyl-CoA in the TCA cycle at isocitrate dehydrogenase, alpha-ketoglutarate dehydrogenase, and malate dehydrogenase.
Which metabolic process directly produces FADH2 in the TCA cycle?
Answer: Succinate → fumarate
Succinate dehydrogenase oxidizes succinate to fumarate using FAD as the electron acceptor, generating FADH2.
What is the primary role of fermentation in microbial metabolism?
Answer: To regenerate NAD+ so glycolysis can continue
Fermentation regenerates NAD+ by transferring electrons from NADH to organic molecules, allowing glycolysis to continue producing ATP.
Which compound serves as the final electron acceptor in aerobic respiration?
Answer: Molecular oxygen (O2)
In aerobic respiration, O2 is the terminal electron acceptor and is reduced to water by cytochrome c oxidase (Complex IV).