Cellular respiration uses one glucose molecule to produce a total of?
28 atps
2 atps
36 atps
24 atps
36 ATP
Cellular respiration uses one glucose molecule to produce a total of 36 ATPs.
Cellular respiration is a metabolic process that occurs in the cells of living organisms, in which glucose and oxygen are converted into energy, carbon dioxide, and water. The process occurs in three main stages: glycolysis, the citric acid cycle (also known as the Krebs cycle), and oxidative phosphorylation (also known as the electron transport chain).
To determine the total number of ATP (adenosine triphosphate) molecules produced from one glucose molecule during cellular respiration, we need to consider all three stages.
1. Glycolysis: In this process, one glucose molecule is broken down into two molecules of pyruvate. During glycolysis, a net gain of 2 ATP molecules is produced.
Total ATP produced so far: 2 ATP.
2. Citric Acid Cycle (Krebs Cycle): Each pyruvate molecule from glycolysis enters the citric acid cycle and produces energy-rich molecules (NADH and FADH2), which will be used in the next step. In one glucose molecule, two pyruvate molecules are produced, so the citric acid cycle will occur two times. One turn of the citric acid cycle produces 3 NADH and 1 FADH2. Since there are two pyruvate molecules formed from one glucose molecule, the total production is:
(3 NADH + 1 FADH2) × 2 = 6 NADH + 2 FADH2.
Additionally, during one turn of the citric acid cycle, one molecule of ATP is formed, and since the cycle occurs twice, the total production is:
1 ATP × 2 = 2 ATP.
Total ATP produced so far: 2 ATP + 6 NADH + 2 FADH2.
3. Oxidative Phosphorylation (Electron Transport Chain): The NADH and FADH2 molecules produced from glycolysis and the citric acid cycle will enter the electron transport chain. Here, the energy from these molecules is used to generate ATP molecules. One NADH molecule produces approximately 2.5 ATP, while one FADH2 molecule produces approximately 1.5 ATP. Considering the 6 NADH and 2 FADH2 molecules produced from the previous stages, we can calculate:
(6 NADH × 2.5 ATP) + (2 FADH2 × 1.5 ATP) = 15 ATP + 3 ATP = 18 ATP.
Total ATP produced so far: 2 ATP + 6 NADH + 2 FADH2 + 18 ATP.
Adding up all the ATP molecules produced from each stage, the total number of ATP molecules obtained from one glucose molecule during cellular respiration is:
2 ATP + 6 NADH + 2 FADH2 + 18 ATP = 24 ATP.
Therefore, the correct answer is 24 ATP.