Problem 7 - Objective Biology for NEET

Question

Glucose \(\rightarrow\) Glu-6-phosphate occurs due to the enzyme (a) Hexokinase (b) Oxidase (c) Hydrolase (d) Lysase

Step-by-Step Solution

Answer

The correct answer is (a) Hexokinase. It is the enzyme involved in the conversion of glucose to Glu-6-phosphate.

Step 1: Understanding the process

Glucose is converted into Glu-6-phosphate to begin the process of glycolysis, which is a metabolic pathway that is part of cellular respiration in the cells. This is a key step where glucose is prepared for further breakdown in later stages.

Step 2: Identifying the enzyme

The enzyme responsible for converting glucose into Glu-6-phosphate is hexokinase. Hexokinase catalyzes the phosphorylation of glucose to produce glucose-6-phosphate, this is the first step of the glycolytic pathway.

Step 3: Choosing the right option

Reviewing the options given, the correct choice, based on our understanding of the biology, is Hexokinase. Neither Oxidase, Hydrolase nor Lysase are involved in the conversion of glucose to Glu-6-phosphate. This substantiates our answer.

Key Concepts

Glucose Phosphorylation

Glucose phosphorylation is a crucial process in cellular metabolism. It marks the first stage in breaking down glucose during glycolysis. This process involves adding a phosphate group to the glucose molecule, transforming it into glucose-6-phosphate. This modification is essential as it traps glucose within the cell. Due to the negatively charged phosphate, glucose-6-phosphate is unable to cross the cell membrane.

• Locks glucose in the cell, ensuring it is used efficiently for energy production.
• Marks glucose for the glycolytic pathway, initiating its breakdown.

Glucose phosphorylation is a prime example of how the body controls energy sources effectively. It sets up the glucose molecule for subsequent steps in metabolism.

Hexokinase Enzyme

Hexokinase is the enzyme that catalyzes the phosphorylation of glucose to glucose-6-phosphate. It acts swiftly after glucose enters the cell. Within the glycolytic pathway, hexokinase is responsible for the very first step.

• Hexokinase works by transferring a phosphate group from ATP to glucose.
• This reaction consumes an ATP molecule, highlighting the investment of energy to gain more in the later stages.
• Hexokinase is found in nearly every tissue, reflecting its essential role in energy management.

By converting glucose to glucose-6-phosphate, hexokinase effectively sets the stage for energy extraction in cellular respiration.

Metabolic Pathway

A metabolic pathway is a series of chemical reactions occurring within a cell. The glycolytic pathway, starting with glucose phosphorylation, exemplifies one of the key metabolic pathways. These pathways transform molecules through enzymatic steps. Glycolysis, for instance, includes 10 enzymatic reactions that break down glucose into pyruvate.

• Metabolic pathways are like an assembly line for energy and molecule production.
• Each step is regulated by specific enzymes, ensuring efficiency and control.
• Byproducts can enter other pathways, showing the interconnected nature of metabolism.

Understanding metabolic pathways helps us appreciate the complexity and coordination in cellular processes.

Cellular Respiration

Cellular respiration is the process by which cells generate energy. It encompasses several metabolic pathways, including glycolysis. This multistep process transforms biochemical energy from nutrients into ATP (adenosine triphosphate).

• Glycolysis occurs in the cytoplasm and is the initial phase of cellular respiration.
• Following glycolysis, cells undergo the Krebs cycle and electron transport chain.
• The goal is to produce maximum ATP, the cell's main energy currency.

Cellular respiration is vital for sustaining biological functions. It governs how energy flows through cells, influencing everything from muscle contraction to brain activity.