In glycolysis, as in all the stages of cellular respiration, the transfer of electrons from electron donors to electron acceptors plays a critical role in the overall conversion of the energy in foods to energy in ATP. These reactions involving electron transfers are known as oxidation-reduction, or redox, reactions.
1. When a compound donates (loses) electrons, that compound becomes _____. Such a compound is often referred to as an electron donor.
2. When a compound accepts (gains) electrons, that compound becomes _ . Such a compound is often referred to as an electron acceptor.
3. In glycolysis, the carbon-containing compound that functions as the electron donor is _.
4. Once the electron donor in glycolysis gives up its electrons, it is oxidized to a compound called .
5. is the compound that functions as the electron acceptor in glycolysis.
6. The reduced form of the electron acceptor in glycolysis is ___.

Also, the substance which itself gets reduced and oxidizes other substance is known as oxidizing agent. Redox reactions occur simultaneously i.e. when one substance gets oxidized then only another substance will get reduced.

During glycolysis, glucose (C₆H₁₂O₆) which is a 6 carbon compound looses electrons to ultimately get converted into a 3 carbon compound known as pyruvate (CH₃COCOOH). During this process, an oxidizing agent known as NAD⁺ accepts the electron and itself gets reduced to become NADH.

The chemical formula of glucose is C₆H₁₂O₆ while the chemical formula of pyruvate is CH₃COCOOH. If we will look at their chemical formulas we can easily detect that glucose has lost hydrogen as compared to pyruvate that means glucose has got oxidized. In glucose, there are 12 hydrogen atoms against 6 carbon while in pyruvate there are only 4 hydrogen atoms against 3 carbon atoms so it simply means glucose has been oxidized in the process because in resultant molecule which is pyruvate there are comparatively less hydrogen atoms.