The Great Electron Chase: Describe the flow of electrons from rain falling on your strawberry garden into the strawberry plant (i. e. through the relevant steps of photosynthesis), and to your urine (water) after eating the strawberry (i. e. through the relevant steps of cellular respiration).

As the rain water is absorbed by the strawberry roots to the leaves, the first step of light independent stage of photosynthesis; Photolysis takes place.

                               H20 = 2H+ + 2e + 2O2.

Generally, the chlorophyll is made up of primary and accessory pigments in its photosystems I and II. These photosystems emitted their electrons through photo activation; these are picked up by electron acceptors; for photophosphorylation in ATPs synthesis. Therefore, these photosystems are positively charged. Hence, PI takes electrons from P II (since it is Cyclic photophosphorylation).Thus P1 is now stabilized, why PII is unstable. To regain its stability, it replaces its lost electrons from the electron of photolysis of water above. This is the electron from the rain water on the (stored in chlorophyll) strawberry. The electron from PI combines with H+and picked up by NAD to NADH. (2H+2e+NADP= NADH).

When the strawberry is consumed, it undergoes digestion and its cellulose metabolized to glucose (the electrons are trapped in the elements C,H,O in the glucose) which flows into the blood stream. As the individual undergoes cellular respiration the glucose with its electrons are the substrate. The glucose, undergoes substrate level phosphorylation (Glycolysis).These electrons are transferred from glucose to the new elements in pyruvate as glucose moves from one stage to another. The electrons are also transferred as part of  H picked up by NAD to NADH. They are transferred from pyruvate to Acetyl, as the latter forms Acetyl Co A with coenzyme A.  

The Acetyl CoA, enters the Krebs’s Cycle, and as, moves from one step to another, these electrons are transferred from one intermediate to another. They are eventually transferred by NADH, FADH2 into the matrix of the mitochondria, where they splits from hydrogen atoms, and carried by electron carriers. As they move from one carries to another, PMF is generated which pumps the H+ across into the inner membranes, to generate the electrochemical gradients for ATPs synthesis, as the protons returns to the matrix.

When these electrons reached the end of the carrier molecule, they are accepted by oxygen the final electron acceptor, to form water. These electrons is transported as water, to the kidney where they are pass through the stages of glomerular filtration, reabsorption, secretion before they are emptied in urine as waste.  

Explanation: