Nature of enzymes: Enzymes are biocatalysts made up of proteins with a specific shape determined by the sequence of amino acids held together by bonds.
Catalysis: Enzymes speed up reactions by bringing reactants together and reducing activation energy.
Amount of enzyme: Enzymes catalyze reactions and are not utilized themselves, so even a small amount of enzyme can start a reaction and catalyze quickly.
Specificity: Enzymes are specific in their action, catalyzing only a single chemical reaction or a group of related reactions.
Active Site: Enzymes have an active site where substrates attach, and the shape of the active site is complementary to the shape of the substrate.
Sensitivity: Enzymes are sensitive to changes in pH, temperature, and substrate concentration.
Cofactors: Some enzymes require cofactors, which are non-protein substances that may be organic (NADP, NAD, and FAD) or inorganic (Zn, Mg, Mn, Fe, Cu, K, and Na), to function.
Types of cofactors: Cofactors can be categorized into two types: prosthetic groups and coenzymes. Prosthetic groups are organic cofactors that are tightly bound to an enzyme. Coenzymes are organic cofactors that are loosely attached to an enzyme.
Increase and decrease of activity: Enzyme activity can be enhanced by activators and decreased by inhibitors.
Feedback reaction: Many enzymes work sequentially in a metabolic pathway to produce a specific product.
Inhibitor: An enzyme inhibitor is a molecule that binds to an enzyme and decreases its activity. Inhibiting the activity of an enzyme can be used to kill a pathogen.
Enzymes are used in various industries. Following are the important uses of enzymes:
Paper industry: Enzymes are used in the paper industry to obtain cellulose for papermaking.
Food industry: Enzymes are used in the food industry to make bakery products and pizza.
Brewing industry: Enzymes are used in the brewing industry to convert sugar into alcohol.
Bio-detergents: Enzymes are used in bio-detergents to remove different types of stains.
Organisms adjust the conditions of their enzymes to produce an optimum rate of reaction. Enzymes may be adapted to function well in extreme conditions where organisms live.
Substrate Concentration
If the enzyme amount is fixed and substrate concentration is increased, the reaction velocity will reach a maximum point. This is because the enzyme molecules are already saturated with the substrate, and excess substrate molecules cannot react until the ones bound to enzymes have reacted and been released.
Temperature
Enzymes are very sensitive to temperature changes, with a narrow range of optimal temperatures for activity. Increasing temperature increases enzyme collisions and reaction rate, but also causes enzyme denaturation, decreasing or stopping the reaction. As temperature increases, the rate of reaction initially increases due to increased kinetic energy, but eventually decreases due to bond breaking.
pH
Enzymes are pH-sensitive due to their protein nature. They work at their maximum rate within a narrow pH range, known as the optimum pH. For example, pepsin works at a low pH, while trypsin works at a high pH. Most enzymes work at neutral pH 7.4. Slight changes in pH above or below the optimum do not permanently alter the enzyme, as the bonds can be reformed. However, extreme changes in pH can denature the enzymes and cause them to permanently lose their function.
