Final answer:
In the third step of glycolysis, NAD+ is reduced to NADH, ATP is synthesized, and pyruvate molecules are formed. The process is critical for energy production in the cell, leading to further ATP generation in subsequent stages of cellular respiration.
Step-by-step explanation:
In the third main event of glycolysis, the electron carrier NAD+ is produced, ATP is synthesized and two pyruvate molecules result. Glycolysis is a multi-step metabolic pathway where a glucose molecule is converted into two pyruvate molecules. The stage you are asking about involves the oxidation of glyceraldehyde-3-phosphate to 1,3-bisphosphoglycerate by the enzyme glyceraldehyde-3-phosphate dehydrogenase, during which NAD+ is reduced to NADH. This step, which does not require an additional input of ATP, is crucial for the eventual production of ATP later in the process.
After this step, 1,3-bisphosphoglycerate is dephosphorylated to generate ATP and 3-phosphoglycerate, meaning that ATP is synthesized during this process. Ultimately, the end product of glycolysis is pyruvate, which has several possible fates depending on the energy needs of the cell. Two molecules of NADH are produced for each molecule of glucose that enters the glycolysis pathway, leading to potential further ATP production in the electron transport chain.