Question

\(\mathrm{RQ}\) for protein is (a) \(0.8\) (b) \(0.7\) (c) \(0.9\) (d) \(0.5\)

Short answer

The correct option is (a) 0.8

Step-by-step solution

Understand basic RQ information

The Respiratory Quotient (RQ) is an important factor in nutrition and metabolism. It defines the ratio of the volume of CO2 produced to the volume of O2 consumed while food is being metabolized. The RQ value differs for every macronutrient - carbohydrates, fats, and proteins.

Identify RQ for protein

The RQ for protein is widely accepted to be around 0.8. This is due to the way proteins are metabolized in our body, which generates roughly the same quantities of CO2 and O2.

Match RQ for protein with given options

Comparing the known value of RQ for protein (0.8) with the provided options, find a match and choose it as the correct answer.

Key concepts

Nutrition and Metabolism

Nutrition and metabolism are fundamental processes that sustain life. Nutrition provides the body with essential nutrients which are crucial for energy, growth, and repair. Metabolism refers to all the chemical reactions occurring within our cells that convert these nutrients into energy and other necessary substances.

Nutrients required by the body are divided into two main categories: macronutrients and micronutrients. Macronutrients are needed in larger amounts, and they include carbohydrates, proteins, and fats. Each of these macronutrients plays a unique role in the body and has distinct metabolic pathways.

Understanding the concept of the Respiratory Quotient (RQ) is essential in nutrition and metabolism. It helps in understanding how different macronutrients are metabolized. RQ is the ratio of carbon dioxide (CO2) produced to oxygen (O2) consumed during metabolism and varies for different macronutrients, providing insights into which type of fuel (carbohydrate, fat, or protein) is predominantly used by the body.

Protein Metabolism

Proteins are complex molecules made up of amino acids, essential for the growth and repair of body tissues. Protein metabolism involves two primary processes: the breakdown of proteins into amino acids and the synthesis of new proteins from these amino acids.

When proteins are metabolized, they go through a series of reactions that involve deamination, where the amino group is removed, and transamination, where an amino group is transferred to another compound. These processes are crucial for producing energy, although less energy is generated from proteins compared to carbohydrates and fats.

The Respiratory Quotient for proteins is typically around 0.8. This lower RQ value reflects the biochemical pathways involved in protein metabolism, indicating that protein oxidation produces almost equal amounts of carbon dioxide and consumes similar amounts of oxygen, but slightly less does so than carbohydrates.

Macronutrients

Macronutrients are the main sources of energy in our diet and consist of carbohydrates, proteins, and fats. Each plays a major role in maintaining body functions and overall health.

**Carbohydrates:** Are the primary energy source for the body. They have an RQ value close to 1.0, indicating efficient metabolism with high CO2 production relative to the oxygen consumed.

**Fats:** Serve as long-term energy storage. They are energy-dense and have a lower RQ value around 0.7, meaning fat metabolism requires more oxygen compared to carbon dioxide produced.

**Proteins:** Are vital for building and repairing tissues and have an RQ value near 0.8. Proteins provide energy, although they are not the primary energy source and are metabolized differently than carbohydrates and fats.

Different RQ values highlight that each macronutrient contributes uniquely to our body's energy needs. Understanding these roles helps us tailor our nutrition to meet specific metabolic demands.