Problem 105 - Objective Biology for NEET

Question

Assertion: When carbohydrates are used as substrate and are completely oxidized, the RQ will be 1 Reason: Equal amount of \(\mathrm{CO}_{2}\) and \(\mathrm{O}_{2}\) are evolved and consumed during the above process.

Step-by-Step Solution

Answer

Both the Assertion and Reason are true and the Reason is the correct explanation for the Assertion. When a carbohydrate is completely oxidized, the RQ is indeed 1 since equal volumes of CO2 and O2 are evolved and consumed during the process.

Step 1: Understanding Respiratory Quotient (RQ)

Respiratory Quotient (RQ) or Respiratory Ratio is a dimensionless number used in calculations of basal metabolic rate (BMR) when estimated from Carbon Dioxide (CO2) production. It's calculated as the ratio of the volume of the total CO2 evolved to the volume of Oxygen (O2) consumed when foodstuffs are oxidized in the body.

Step 2: Validating Assertion

When carbohydrates are oxidized, they usually follow the empirical formula \(C_{n} (H_{2}O)_{n}\). This means that when they are fully oxidized, they consumed one molecule of O2 and produce one molecule of CO2 per carbon atom in the carbohydrate. Therefore, the volume of CO2 produced is equal to the volume of O2 consumed, which makes the RQ equal one. So, the Assertion 'When carbohydrates are used as substrate and are completely oxidized, the RQ will be 1' is true.

Step 3: Validating Reason

The Reason provided is 'Equal amount of CO2 and O2 are evolved and consumed during the above process.' This is true as explained in the previous step, the oxidation of carbohydrates involves the production of an equal volume of CO2 and consumption of O2, leading to an RQ of 1. Thus, the Reason is the correct explanation of the Assertion.

Key Concepts

Carbohydrate Oxidation

Carbohydrate oxidation is a process where carbohydrates are broken down to release energy. These carbohydrates typically follow the chemical formula \( C_n(H_2O)_n \).
In this process, the carbohydrates react with oxygen (O\(_2\)) to produce carbon dioxide (CO\(_2\)), water, and energy.
This is an essential metabolic pathway that provides energy to cells in the body. During complete oxidation, one molecule of glucose will use six molecules of O\(_2\) to produce six molecules of CO\(_2\).

• Carbohydrates serve as energy sources for cellular processes.
• The process primarily occurs in the mitochondria within cells.
• Complete oxidation of carbohydrates provides a Respiratory Quotient (RQ) of 1.

The RQ value signifies that equal volumes of oxygen are consumed as carbon dioxide is produced.

Basal Metabolic Rate

Basal Metabolic Rate (BMR) is the rate at which your body uses energy while at rest to maintain vital functions like breathing and keeping warm.
This is a critical measure because it represents the minimum energy required to maintain the body's normal functions.
Understanding BMR helps in managing weight as it indicates how many calories are needed to maintain the body's basic functions.

• BMR is influenced by factors such as age, gender, weight, and muscle mass.
• It’s typically higher in people with more muscle.
• Knowing your BMR can help in creating effective dietary plans.

RQ is often used in BMR calculations because it helps estimate energy expenditure based on CO\(_2\) production and O\(_2\) consumption.

Carbon Dioxide Production

Carbon dioxide production is a natural result of metabolic processes where energy is generated.
When carbohydrates are oxidized, CO\(_2\) is a major byproduct. This gas is removed from the body through respiration.

• The volume of CO\(_2\) produced is crucial for calculating the RQ.
• High CO\(_2\) levels in the blood can lead to respiratory issues.
• Efficient removal is necessary for maintaining the body's pH balance.

Monitoring CO\(_2\) levels helps in understanding metabolic rates and energy expenditure.

Oxygen Consumption

Oxygen consumption refers to the utilization of oxygen by the body to produce energy from nutrients.
This process is vital for sustaining life, as it powers cellular activities. In carbohydrate oxidation, oxygen combines with glucose to produce energy, water, and CO\(_2\).

• Oxygen uptake is measured in order to calculate the RQ.
• Higher oxygen consumption typically indicates increased energy use.
• It's crucial for aerobic processes which support endurance activities.

Balancing oxygen intake with CO\(_2\) production is essential for efficient metabolic function.