Question

production of the water of at the end of respiration​

Answer 1

Explanation:

We might only breathe in oxygen, but that isn't the only thing we take in for cellular respiration. We also take in glucose or other sugars that we’re looking to break down into energy. These saccharides, combined with oxygen, will allow water to be produced as a waste product.

Cellular respiration produces a total of 6 molecules of water for every glucose it breaks down. Recall that (aerobic) cellular respiration is composed of three steps: glycolysis, the citric acid cycle, and oxidative phosphorylation.

Glycolysis produces 2 of the 6 total molecules of water in cellular respiration. These 2 molecules are released as waste product in the 9th enzyme-catalyzed reaction of glycolysis. In this step, 2-phosphoglycerate is converted to phosphoenolpyruvate by the enzyme enolase. This reaction produces 1 molecule of H2O, but since glucose is originally split into two pyruvate, this reaction actually occurs twice per glucose and so yields 2 H2O.

Okay, so we’ve accounted for a third of the H2O produced during respiration. The next bit of H2O waste produced comes from the citric acid cycle. After acetyl coA has been converted to citric acid, the enzyme aconitase then converts the citric acid to cis-Aconitic acid. This reaction releases 2 more molecules of water.

The last part of the water waste comes from oxidative phosphorylation. In cytochrome c (the final protein complex of the electron transport chain), electrons are transferred to one oxygen ion and two hydrogen ions (protons), to form water (H[math]_2[/math]O.)

This is where the water in respiration comes from.