Enzymes

These proteins may be referred to as catalysts or biological agents that are capable of raising the velocity of chemical changes by lowering the activation energy needed for such changes. They are specific because they only catalyze specific reactions, they bind with their specific substrates to form an enzyme-substrate complex and affect the change in the substrate into one single product without getting used up.

The notable features of enzymes include the fact that these substances interact with specific substrates involved in the reaction, and appreciably higher energy is needed to continue the reaction past a certain point. Such specificity and rate increase the efficiency of enzymes in catalyzing reactions that could maintain the efficacy and nutritional value of processed foods.

Enzymes Naming

The International Union of Biochemistry and Molecular Biology is entrusted with designating names to enzymes in addition to assigning a number to identify them.

The naming of enzymes follows a systematic and structured approach designed to convey key information about their function and origin. Enzyme names typically consist of two parts: a prefix denoting the substrate or type of reaction catalyzed, and a suffix indicating its enzymatic nature. This nomenclature system helps scientists and researchers quickly understand an enzyme’s role and characteristics.

1. Prefix (Substrate or Function): The prefix of an enzyme name often determines the substrate on which the enzyme acts or the type of reaction it catalyzes. For example:

• Lipase: Acts on lipids (fats).
• Amylase: Acts on starch (amylose).
• Protease: Acts on proteins.
• Polymerase: Catalyzes polymerization reactions.

2. Suffix (Enzyme Type): The suffix of the enzyme name usually indicates its enzymatic nature or class. Common suffixes include:

• -ase: This suffix denotes that the molecule is an enzyme. For example, lipase, amylase, protease, etc.
• -synthase/-synthetase: Used for enzymes that synthesize molecules rather than break them down
• Examples include DNA polymerase (which synthesizes DNA) and ATP synthase (which synthesizes ATP).

3. Numbering and Specificity: Enzymes are often categorized into families and subclasses based on similarities in structure, function, and evolutionary origin. These classifications help researchers understand relationships between different enzymes and predict their properties.

4. Organism-specific Names: Some enzymes are named after the organism from which they were first identified or isolated. For example:

• Pepsin: Named after its initial isolation from the stomach (Greek: “Pepsis” meaning digestion).

5. Historical or Descriptive Names: Occasionally, enzyme names may reflect historical context or a descriptive aspect of their function. For instance:

• Catalase: Named for its role in catalyzing the breakdown of hydrogen peroxide.
• Superoxide dismutase: Describes its function of dismutating superoxide radicals.

Enzymes Classification

The International Union of Biochemistry and Molecular Biology gives the number to the enzyme to classify them this number is called the EC number

EC number

There are Six classes of enzymes depending upon the reaction they catalyzed.

EC number consists of 4 digits a,b,c, and d.

• “a” is a class
• “b” is a subclass
• “c” is sub-subclass
• “d” is sub-sub-subclass

EC classifications

• EC 1. Oxidoreductases
• EC 2. Transferases
• EC 3. Hydrolases
• EC 4. Lyases
• EC 5. Isomerases
• EC 6. Ligases

EC 1. Oxidoreductases

These enzymes catalyze the oxidation and reduction reactions. Oxidation, addition of oxygen, and removal of hydrogen and electrons. Reduction, removal of oxygen, and addition of hydrogen and electrons. these are also known as reductases oxidases and hydrogenases.

EC 2. Transferases

It catalyzes the transfer of an atom or group of atoms from one molecule to another molecule. For Example: Hexokinase plays a role in the transfer of phosphate group from one hexose to another.

EC 3. Hydrolases

A group of enzymes that catalyze the cleavage of bonds in the presence of water. it catalyzes hydrolytic reactions. For example lipases and proteases.

EC 4. Lyases

It catalyzes the reaction in which the breaking of bonds occurs without hydrolysis. It breaks the chemical bond and forms a double bond or adds atoms or groups of atoms to the double bond.

EC 5. Isomerases

A group of Enzyme catalyzes isomerization reactions involving cis-trans isomerizations. For Example Phosphohexose and isomerase.

EC 6. Ligases

It catalyzes the formation of two bonds along with the ATP cleavage. For example Glutamine synthetase