Cellular respiration harvests the most chemical energy from which of the following?
a) transferring electrons from organic molecules to pyruvate
b) substrate-level phosphorylation
c) generating carbon dioxide and oxygen in the electron transport chain
d) chemiosmotic phosphorylation
e) converting oxygen to atp

The answer is D-  Chemiosmotic phosphorylation

Explanation:

Cellular respiration is defined as a set of metabolic reactions and processes that take place in the cells of organisms to convert biochemical energy from nutrients into Adenosine triphosphate (ATP), and then release waste products. It is the process of breaking down sugar into a form that the cells can use as energy. Respiration is one of the key ways in which a cell releases chemical energy to fuel cellular activity. Usually, this process uses oxygen and is called aerobic respiration.

Chemiosmotic phosphorylation is the third pathway that produces ATP from inorganic phosphate and an ADP molecule. It is part of oxidative phosphorylation.

Most of the ATP produced by aerobic cellular respiration is made by oxidative phosphorylation and this works by the energy released in the consumption of pyruvate being used to create a chemiosmotic potential by pumping protons across a membrane.

it provides an alternative energy pathway for the reaction to proceed.

a catalyst is a substance that speeds up the rate of a chemical reaction but is not consumed during the course of the reaction.

catalysts increase the rate of reaction without being used up. they do this by lowering the activation energy needed. with a catalyst, more collisions result in a reaction, so the rate of reaction increases. different reactions need different catalysts.

a catalyst works by providing an alternative reaction pathway to the reaction product. the rate of the reaction is increased as this alternative route has a lower activation energy than the reaction route not mediated by the catalyst.