The number of ATP molecules produced by oxidative phosphoryl…
The number of ATP molecules produced by oxidative phosphorylation is imprecise due to variability in the structure and function of ATP synthase. Which of the following factors contributes to this imprecision? Contextual Information:The number of ATP molecules produced by oxidative phosphorylation is imprecise due to variability in the number of subunits in the c-ring of the Fo region of ATP synthase. The c-ring can have between 8 and 15 subunits, with each subunit requiring 1 proton for rotation. A full 360-degree rotation of the c-ring produces 3 ATP molecules. Therefore, the proton-to-ATP ratio depends on the number of c-ring subunits. For example: If the c-ring has 10 subunits, it requires 10 protons for one full rotation. Since 3 ATP molecules are produced per rotation, the proton-to-ATP ratio is 10 ÷ 3 ≈ 3.33 protons per ATP. If the c-ring has 12 subunits, it requires 12 protons for one full rotation. The proton-to-ATP ratio is 12 ÷ 3 = 4 protons per ATP. If the c-ring has 8 subunits, it requires 8 protons for one full rotation. The proton-to-ATP ratio is 8 ÷ 3 ≈ 2.67 protons per ATP. Additionally, for each NADH, approximately 10 protons are pumped across the inner mitochondrial membrane, while about 6 protons are pumped for each FADH₂. The variability in the number of c-ring subunits and the protons pumped by NADH and FADH₂ contribute to the imprecision in calculating ATP yield.
Read Details