Substrate.
NAD+ is a substrate in redox reactions because it serves as a coenzyme that accepts and donates electrons during cellular respiration to facilitate energy production.
As glucose is broken down, some energy is captured by substrate-level phosphorylation, some energy is captured by the reduction of NAD+, but most of the energy is still in the end product, Pyruvate.
Glucose can be both a substrate and a product in biochemical reactions. It can serve as a substrate in processes such as glycolysis where it is broken down to produce energy, and as a product in processes like photosynthesis where it is synthesized from carbon dioxide.
Reactant
An enzyme combines with a substrate to form a product through a series of chemical reactions. The substrate is the specific molecule that the enzyme acts upon, while the product is the end result of the enzyme catalyzing the reaction.
The substrate is the substance (or substances) that attaches to the enzyme's active site before the reaction occurs.The product is the substance (or substances) that is formed after the enzyme has worked on the substrate.///
Substrates are the products of enzyme activity when metabolism occurs. For example: with glycolysis hydrogen is a substrate that is carried to the electron transport chain by NAD and FAD which then become NADH and FADH with the added hydrogen. I am just a student though, i was looking for the same answer. Just know what is produced as a result of a particular reaction and you will have your substrates. Shane
substrate
The substance on which enzymes act are called substrates.
Your Mother
NAD is a coenzyme.Its role is as a hydrogen acceptor when it is involved in the oxidation of glucose (cell respiration). Is is written as NAD+, and after accepting hydrogen it becomes the reduced form, NADH.NADH in turn acts as a hydrogen donor when it becomes oxidized to reform NAD+.
The target molecule for an enzyme is called the substrate. Enzymes bind to specific substrates and catalyze chemical reactions to convert the substrate into a product.