What makes something a substrate such as NAD+, ATP, and glucose?

Answer 1

Hello Affar,

In chemistry, a substrate is a compound that reacts with a reagent to form a product (pretty straightforward).

In biochemistry/molecular biology lingo, a "substrate" is a molecule that is acted on by an enzyme. Let's use your examples.

Glucose: hexokinase is an enzyme that phosphorylates glucose to form glucose-6-phosphate.

ATP: ATP synthase is an enzyme that catalyzes the formation of ADP and Pi to form ATP.

NAD+: ferredoxin-NAD+ reductase oxidizes ferredoxin and reduces NAD+ to form NADH.

Importantly, protein can also be substrates of other proteins as in the case of protein phosphorylation, glycosylation, etc.