Mechanism of Enzyme Action

The human body has many cells, tissues, and organs that all operate together. The body produces enzymes. In order to follow the body clock, these enzymes manage biological functions like respiration and reproduction. They are vital to both human and animal survival. They are mostly proteins that act as catalysts in biological processes.

The enzyme interacts with a “substrate” molecule in the human body to initiate biological action. They are then turned into “products”. Except for RNA-related enzymes, most have proteins. Enzymes are found in most human and animal organs and cells. Intracellular enzymes aid in metabolic activity. Enzymes are formed up of amino acid chains and have a three-dimensional structure. Enzymes are temperature and pH sensitive, and lose function as pH or temperature changes. The size of the amino acid molecules varies.

Enzymes are classified as oxidoreductases, transferases, hydrolases, lyases, isomerases, and ligases. Oxidoreductases are enzymes that transport electrons and control oxidation. Transferases are enzymes that help move substances from donors to receptors in the body. Hydrolases aid in the body’s hydrolysis function. Lyases add ammonia, water, and CO2 to the bonds.

Enzyme Activity

Two ideas were offered to comprehend enzyme mechanism and activity. Them:

1. The Key and the Lock Hypothesis

Emil Fischer proposed this concept in 1894. This idea explains how enzymes work. This hypothesis states that enzyme and substrate molecules have certain geometric forms. The lock and key paradigm posits that enzyme active sites work as a lock with certain chemicals like -COOH and -SH. Only certain substrate complexes can open these enzyme molecules. This concept explains enzyme specificity and manner of action. The substrate interacts with the enzyme complex’s active site to generate an enzyme-substrate complex. This complex undergoes chemical transformations, finally forming a product. Upon formation, this substance leaves the active site and enters the surrounding area. So the active site is ready for new substrates. According to this concept, a small amount of enzyme can act on massive substrate molecules. So the enzymes are not consumed in the reaction and can be reused. It also helps us comprehend competitive inhibition.

2.Induced fit Hypothesis:

In 1960, Koshland suggested this concept. This hypothesis is quite distinct from the previous one. It states that the enzyme’s active site is flexible and may adapt to the substrate’s nature, forming an active site complementary to the substrate. It is easy to see how a hand changes the glove, much as an active site changes the chemical substrate. The substrate enters the enzyme’s active site. The active site structure of an enzyme is thus flexible. The active site of an enzyme has two types of groups. The other is a catalytic group. The buttressing group supports the substrate, while the catalytic component explains enzyme catalysis. When the buttressing group contacts the substrate, modifications occur in the active site, bringing the catalytic group closer to the substrate connections that must be broken. The two models above assist us comprehend and describe enzyme function.

Catalysis by Enzymes

Enzymes are responsible for high chemical conversion rates. The substrates become products. The substrates bind to the enzyme’s active site, causing modifications in the enzyme-substrate complex, and so forming a product. This enzyme-substrate complex forms for a short time and is called transitory. The transitory state structure occurs when the substrate binds to the enzyme’s active site. Then bonds are created and a final product is formed. Activation energy is necessary to initiate a reaction. Enzymes work by reducing reaction activation energies.

Action of Enzymes

Each enzyme molecule has an active site. An enzyme-substrate complex forms when the substrate contacts the enzyme. The enzyme-substrate complex transforms into an enzyme-product complex, which is then separated. This way, the enzyme isn’t used up. The catalytic cycle helps explain enzyme function by illustrating:

1.The active site binds the substrate.

2.This changes the structure of the enzyme.

3.Making and breaking bonds generate the enzyme-product complex.

4.The enzyme is released from the product and is ready for a new batch of substrates.

Factors Influencing Enzyme Catalysis

Three factors influence enzyme catalysis mechanism:

1.Enzyme catalysis acts in a narrow temperature range. In both extremes, enzyme activity is reduced. Low temperature inactivates enzymes, while high temperature denatures their structure.

2.Similar to optimum temperature, optimum pH concentration is essential for enzyme action. Enzyme activity is reduced by pH changes. Some enzymes work well in acidic, while others work well in alkaline. Every enzyme has an optimal pH where it works best.

3.A substrate acts on enzymes to transform it into a product. Enzyme velocity increases with substrate concentration.

Biochemical Enzyme Action Mechanism

The compound’s form changes to cause physical changes. PHYSICAL CHANGES do not break bonds During a chemical reaction, new bonds are generated and broken. It is a physical transformation when ice melts into water. A chemical change is hydrolysis of starch into glucose. These processes’ rate is the amount of product created per unit of time. A direction to rate is termed a velocity. Temperature affects chemical and physical reactions. There are many enzymes, each with a specific catalytic activity or chemical or metabolic reaction. A metabolic route is one where one enzyme catalyzes multiple processes. A metabolic pathway with one or two extra reactions produces a range of end products. This helps us comprehend enzyme function in biochemistry.

Conclusion

As stated previously, enzymes are proteinaceous and catalyze many biological and metabolic processes. The Lock and Key theory and the Induced Fit model are two hypotheses proposed to explain enzyme action. Enzymes have an active site on them where the substrates bind and transform into the product. As the enzyme is not employed in the reaction, it can be reused. Temperature, pH, and substrate concentration all influence enzyme function.