2. WHAT IS ENZYMES?
An enzyme is a macromolecule that act as a catalyst and speeds up the rate of a chemical
reaction by lowering the activation energy in living organism.
For example An enzyme speeds the rate of chemical reaction by reducing its activation
energy(Ea) without affecting the free energy change(DG) for a reaction.
4. Biological functions
1. They are among the remarkable biomolecules known because of their extraordinary specificity and
catalytic power.
2. Enzymes helps to break food into smaller substances through the process of digestion.
3. Converting of glucose to fructose to form sucrose and improves animal’s energy level.
For example,
Glucose (C6H1206) + Fructose (C6H12O6) = Sucrose (C12H22O11).
4. Enzymes helps to cause process of digestion, by converting a specific set of reactants(called
substrates) into specific products. For example,
5. For example,
*Lipases enzyme breakdown lipids.
*Amylases is enzyme which assist in the breakdown of carbohydrates.
*Pepsin is used to breakdown protein into peptides, its works at very acidic PH(1.5)
*One of the fastest enzyme in the body is catalase because, its used to breaks down hydrogen
peroxide, a waste product of cell metabolism into water and oxygen.
*All catalysts lower the energy barrier, allowing the reactants(substrates) to react faster forming the products
6.
7. Specificity(lock and key model)
Specificity is the ability to enzyme to choose it exact substrate.
The specificity of an enzyme is attributed to a compatible fit between the shape of its active site
and the shape of substances(enzyme molecule).
For example,
10. Inhibition
* Inhibitors are substances(molecules) that slows down or stop an enzyme catalyzed.
If the enzyme inhibitor bind to the enzyme by weak interactions, and also resemble the normal substrate
molecule is reversible inhibitor.
The inhibitor that attaches to the enzymes by covalent bonds is usually irreversible.
* There are two types of inhibition.
1. Competitive inhibitor: is reversible inhibitor and resemble the normal shape of substrate molecule.
2. Non-competitive inhibitor: Do not resemble directly or compete with the substrate to bind to the enzyme at
the active site, but they are also reversible.
