Problem 135 - Arihant Objective Approach to Organic Chemistry for IIT JEE and NEET all Medical Entrances Part 4

Question

The function of enzyme in the living system is to: (a) transport of oxygen (b) provide immunity (c) catalyse biochemical reactions (d) provide energy

Step-by-Step Solution

Answer

Enzymes catalyse biochemical reactions.

Step 1: Understanding the Role of Enzymes

Enzymes are biological molecules, typically proteins, that act as catalysts in living organisms. Their primary role is to speed up biochemical reactions without being consumed in the process. They ensure that necessary reactions occur quickly and efficiently to sustain life.

Step 2: Analyzing the Options

Let's evaluate each given option: 1. Transport of oxygen is primarily the function of hemoglobin in the blood, not enzymes. 2. Immunity involves the immune system with antibodies and other molecules, not directly enzymes. 3. Enzymes catalyze biochemical reactions, which is consistent with their role as catalysts. 4. Energy is provided through metabolic processes where enzymes are involved, but they do not directly provide energy themselves.

Step 3: Selecting the Correct Option

Based on the analysis, the function that directly aligns with the role of enzymes is catalyzing biochemical reactions. This is their main role in the body, facilitating reactions necessary for survival.

Key Concepts

Biochemical Catalysts

Enzymes are often referred to as biochemical catalysts because they speed up the rate of chemical reactions in biological systems without being consumed in the process. This is crucial because many biochemical reactions that sustain life happen at a pace that is too slow to be effective without enzymes. By lowering the activation energy—the energy barrier that must be overcome for a reaction to occur—enzymes make it easier for reactions to take place.

• Enzymes alter the reaction pathway to one with a lower activation energy.
• They are specific to the reactions they catalyze, often binding with a substrate to form an enzyme-substrate complex.
• After the reaction, the enzyme releases the product and can be used again.

This ability to accelerate reactions makes enzymes indispensable in both intracellular and extracellular biochemical processes.

Biochemical Reactions

Biochemical reactions involve the transformation of molecules inside living organisms. These reactions are part of metabolic pathways where molecules are continuously converted to sustain life. Cellular processes such as digestion, energy production, and DNA replication rely heavily on biochemical reactions.

• Reactants, known as substrates in these contexts, are the starting materials for reactions.
• Enzymes facilitate the conversion of substrates into products through a series of controlled, step-wise reactions.
• These can include catabolic reactions that break down molecules to release energy, and anabolic reactions that build up molecules and store energy.

Without the orderly conduct of biochemical reactions, cells would not be able to perform essential functions or respond to environmental changes efficiently.

Role of Enzymes

The primary role of enzymes in living systems is to serve as catalysts for biochemical reactions, enabling complex metabolic processes to occur at body temperature and at a rate that sustains life. Through specificity and efficiency, enzymes ensure that cell functions proceed smoothly.

• Enzymes possess specific active sites that bind to substrates, facilitating precise interactions among molecules.
• This specificity helps regulate and control metabolic pathways, ensuring that cells maintain homeostasis.
• Furthermore, enzyme activity can be regulated by factors such as temperature, pH, and the presence of inhibitors or activators.

Enzymes play a foundational role in nearly every biological process, from DNA replication to the breakdown of nutrients, showcasing their indispensable presence in life as we know it.