ATP yield and efficiency Original Scenario-Based Download PDF

Questions

1. 1.

   A bio-engineer aboard an interstellar bio-dome develops an artificial eukaryotic cellular tissue, dubbed Bios-9, designed to harvest metabolic energy from glucose with optimal energetic economy. Although complete combustion of glucose releases roughly 2870 kJ/mol of standard free energy, Bios-9 consistently captures about 34% of this total, generating 30 to 32 ATP molecules per glucose rather than the theoretical maximum of 38 ATP. Which of the following best explains why the actual ATP yield and energetic efficiency in such aerobic eukaryotic systems remain below the theoretical ceiling?

   • A) Cytosolic glycolysis consumes more ATP than oxidative phosphorylation can synthesize, causing an unavoidable net deficit.
   • B) Spontaneous direct oxidation of glucose by cytoplasmic enzymes dissipates the majority of usable free energy as luminescent photon bursts.
   • C) A significant portion of the proton-motive force is diverted to drive the transport of essential metabolites across the inner mitochondrial membrane, alongside basal proton leakage.
   • D) The citric acid cycle switches direction during aerobic respiration to consume ATP in order to deposit storage polysaccharides inside the matrix.