Question

In mitochondria, with the complete breakdown of glucose, about how many molecules of ATP can be produced for each molecule of glucose oxidized?

1) 2
2) 12
3) 30
4) 50

Answer 1

In mitochondria, the complete breakdown of glucose through oxidative phosphorylation yields approximately 30 molecules of ATP, crucial for cellular energy supply. Thus the correct option is (3) 30.

Step-by-step explanation:

Mitochondria play a crucial role in cellular respiration, specifically in the production of adenosine triphosphate (ATP) from glucose. The complete breakdown of one molecule of glucose through oxidative phosphorylation in the mitochondria yields approximately 30 molecules of ATP. This process occurs through a series of biochemical reactions in the electron transport chain (ETC) and the subsequent generation of a proton gradient across the inner mitochondrial membrane.Thus the correct option is (3) 30.

In the initial stages of cellular respiration, glycolysis occurs in the cytoplasm, producing two molecules of ATP. Subsequently, the pyruvate molecules generated in glycolysis enter the mitochondria, where they undergo the Krebs cycle. This cycle produces electron carriers (NADH and FADH₂), which transfer electrons to the ETC. As electrons move through the ETC, protons are pumped across the inner mitochondrial membrane, creating a proton gradient. The flow of protons back into the mitochondrial matrix through ATP synthase leads to the synthesis of ATP.

The chemiosmotic coupling of electron transport and ATP synthesis in mitochondria is an energy-efficient process. The theoretical maximum yield of ATP from the complete oxidation of one molecule of glucose is approximately 38, but due to the energy cost of transporting molecules across membranes, the practical yield is around 30 ATP molecules. This efficient conversion of glucose to ATP in mitochondria is essential for providing energy to various cellular activities, ensuring the proper functioning of living organisms.

Answer 2

For every molecule of glucose completely oxidized in mitochondria, approximately 36 ATP molecules are produced under optimal conditions, with a theoretical maximum of 38 ATP molecules. The closest multiple-choice option is (3) 30, although this doesn't exactly match the calculated result.

Step-by-step explanation:

In the process of aerobic respiration within mitochondria, the complete breakdown of glucose can yield approximately 36 molecules of ATP for each molecule of glucose when conditions are optimal. This high-yield energy production occurs through various steps, starting with glycolysis, then moving through the transition phase to produce acetyl-CoA, continuing through the citric acid cycle (also known as the Krebs cycle), and concluding with oxidative phosphorylation at the electron transport chain (ETC). However, the actual amount of ATP produced can sometimes be less than 36 due to the cost of transporting NADH into the mitochondria and other factors. The theoretical maximum yield under ideal conditions is 38 ATP molecules per glucose molecule, but this is usually a bit lower in reality.

The closest multiple-choice option is (3) 30, although this doesn't exactly match the calculated result.