What are Enzymes and Their Classifications

Enzymes have various applications in the field of healthcare that act as diagnostic tools, therapeutic agents, markers, and research purposes. In clinical diagnostics, the measurement of specific enzyme levels in blood or other body fluids can provide valuable information about various medical conditions. For example, elevated levels of enzymes like Creatine kinase (CK) and troponin can indicate myocardial infarction (heart attack), while abnormal levels of liver enzymes like alanine aminotransferase (ALT) and aspartate aminotransferase (AST) can signal liver disease. Therefore, knowing about enzymes and their classification is crucial for all pathology lab technicians and health professionals.

So what exactly are enzymes?

Enzymes are proteins that act as biological catalysts. Their role is to accelerate the rate of chemical reactions that are essential for life processes. Without enzymes, many of these vital reactions would occur too slowly to sustain living systems.

Enzymes are highly efficient and selective in facilitating specific chemical reactions. They are able to bind to reactant molecules called substrates, holding them in optimal orientations to undergo chemical changes and formations of new products. Enzymes themselves are not consumed or permanently altered during these reactions.

Enzymes derive this catalytic capability from their 3D protein structures. Folded into these intricate shapes are active sites – where substrates bind and chemical reactions happens. The unique geometries and chemical environments of active sites enable enzymes to catalyse reactions with incredible precision and efficiency.

Classifications of Enzymes

There are thousands of different enzymes found in cells, each enzymes have its own specialized function. Therefore to differentiate them enzymes are classified into several broad categories based on the types of reactions they catalyse:

1. Oxidoreductases

These enzymes catalyse oxidation-reduction reactions involving electron transfers. Examples include catalase which breaks down hydrogen peroxide, and the enzymes involved in cellular respiration.

2. Transferases

This class od enzymes transfer functional groups like amino, phosphate, and acyl groups between different molecules. Transaminases and kinases are common transferases you may encounter.

3. Hydrolases

These enzymes catalyse hydrolysis reactions – breaking down compounds by adding water molecules across covalent bonds. Example include proteases that digest proteins and lipases that break down fats.

4. Lyases

Lyases catalyse non-hydrolytic addition or removal of groups from substrates. Example is carbonic anhydrase which aids CO2 transport.

5. Isomerases

This class of enzymes catalyses isomerization – intramolecular rearrangements within a single molecule. Isomerases are involved in metabolic pathways like glycolysis.

6. Ligases

These enzymes catalyse synthesis by joining two molecules together with covalent bonds, using energy from ATP. DNA ligase is critical for repairing broken nucleic acid strands.

Understanding how different enzymes are classified based on their reaction types provides a systematic way to study their diverse roles in biological systems. As vital protein catalysts, enzymes are fundamental to pathology, diagnostics, therapeutics, and essentially all areas of medicine and healthcare. Developing this core knowledge helps build a strong foundation for laboratory work and clinical practice.