How can we determine if an enzyme will work with a specific substrate?
Enzymes are very specific in their action that's why each enzyme can be activated by it's specific substrate.
Chemistry behind it is that
- An enzyme is three dimensional globular protein that has specific composition due to its component amino acids.
- It also has a specific shape.
- An enzyme can catalyze only one reaction.
- And in case of a different substrate( inhibitor) , the active site of enzyme fails to detect it.
- Or even if that substrate has some structural similarity with the specific substrate of enzyme. That substrate is accepted by binding but can't activate the catalytic site.
Succinic acid is a substrate of succinic dehydrogenase (enzyme). Molonic acid has structural similarity with succinic acid. So, in some cases molonic acid occupy the binding site of succcinic dehydrogenase but can't activate its catalytic site. So no enzymatic activity occurs.
That's why a particular enzyme by virtue of its specificity recognizes and reacts with its particular substrate.
Binding and catalytic sites are collectively called active site .
- Binding site binds the specific substrate.
- Catalytic site transforms the specific substrate into products.
Hope it helps...