[Biology Class Notes] on Enzymes Pdf

Enzymes can be defined as the catalysts that are found in the living cells and they are constituted of protein substances, which help in facilitating the complex biochemical as well as metabolic reactions. Since they are catalysts, the enzymes don’t directly participate in biological reactions but they assist with their efficient occurrence. This is why an enzyme can be brought to use usually without getting exhausted. 

Some of the examples of the enzymes are Protease, and Proteases, Lipase, Amylase, and Lactase. The enzymes are formed when the specific number (a few thousand) of the amino acids are linked together within the chains using amide or peptide bonds. The enzymes are generally added in beverages, bread, chocolates, washing powders, pre-digested baby foods, and curd for effective and efficient preparation. 

The Structure of the Enzymes

Enzymes are made using several amino acids and thus they are structured similarly to the proteins. The enzyme has an active site or the substrate-binding site. This is the site where the chemical reaction takes place and the substrate gets attached. The enzyme is able to break the bigger molecule into simpler molecules or vice versa. 

The enzyme also has a site known as the inhibitor site. The inhibitor site tends to be functional when the enzyme is in the inactivated stage. Enzymes also have the model of the lock and key structure. In 1958, scientist Daniel Koshland suggested that the active sites of the enzymes are modifiable and flexible, and thus can be reshaped by interactions with corresponding substrates. 

Fit Model of the Enzyme

The common equation which can be used to describe the functioning of the enzyme through enzyme-substrate reaction is Substrate + Enzyme  = (Substrate-Enzyme) > (Product-Enzyme or the intermediate) = Product + Enzyme. 

The interaction of the enzyme-substrate can be better explained with the lock and key structure mechanism. The lock is represented by the enzyme whereas the key is represented by the substrate. Each substrate belongs specifically to its enzyme, similar to the keys belonging to the specific locks. 

Affecting Factors for the Enzyme

• The presence of the right temperature is essential for the functioning of the enzyme. If the temperature is above the specified limit then it can completely destroy the enzyme and lead to its disintegration thus rendering it useless.

• The correct extent of the basic, acidic, or natural environment is key. 

• Some specific vitamins and non-protein substances, in humans as well as animals, might serve as “co-factors” for helping enzymes function efficiently by assisting in the binding process. The presence or absence of these “co-factors” has an impact on the working of enzymes.

• The presence of an inhibitor can have an adverse impact on the functioning of the enzyme.

• The concentration of enzymes is also a major factor that has a big impact on the reaction.

Action and Nature of the Enzymes

• As we have discussed, the enzymes are naturally protein and thus they are made of various amino acids. 

• The enzymes are formed by paracrine glands and exocrine glands and they are transferred to the required place viaducts. 

• Enzymes are the catalysts that speed up the chemical reaction within the body.

• Enzymes lower the required activation energy for the chemical reaction and thus less energy is needed for carrying the reaction forward.