Problem 70 - Objective Biology for NEET

Question

The total percentage of \(\mathrm{O}_{2}\) transported by haemoglobin or \(\mathrm{RBC}\) is (a) \(3 \%\) (b) \(97 \%\) (c) \(70 \%\) (d) \(7 \%\)

Step-by-Step Solution

Answer

The correct answer is (b) 97%

Step 1: Understanding the Role of Haemoglobin and Red Blood Cells (RBC)

Haemoglobin is the protein inside red blood cells that carries oxygen. It gives the red blood cells their color. Red blood cells are also known as RBCs. They are the most common type of cell in the blood, and they carry oxygen from the lungs to the body's tissues.

Step 2: Recalling or Researching the Percentage of Oxygen Transported by Haemoglobin/RBC

The percentage of oxygen transported by Haemoglobin or RBC refers to the amount of oxygen in the body that is being carried through the blood by these means. You can solve this problem by recalling the correct percentage from your study or research.

Key Concepts

Haemoglobin

Haemoglobin is a crucial protein found in red blood cells. It acts like an oxygen taxi, picking up oxygen in the lungs and delivering it to tissues throughout the body. This protein has a special structure that enables it to bind to oxygen molecules effectively. Haemoglobin gives red blood cells their distinctive red color because it contains iron, which actually binds the oxygen molecules.

The ability of haemoglobin to carry oxygen is dependent on both the iron in its structure and the shape of the protein itself. When oxygen binds to haemoglobin, the protein changes shape slightly, making it easier to pick up more oxygen. This is the basis of what's known as cooperative binding. Moreover, this oxygen transport is absolutely vital for cellular respiration, the process by which cells produce energy.

Red Blood Cells (RBC)

Red Blood Cells, often abbreviated as RBC, are the most prevalent cell type in our blood. Their primary job is to deliver oxygen from the lungs to the rest of the body. RBCs are uniquely designed for this task with their biconcave shape, which increases the cell's surface area for oxygen absorption.

These cells are packed full of haemoglobin, the protein that directly binds to oxygen. RBCs are produced in the bone marrow and have a life span of about 120 days. They are flexible to navigate through the smallest of blood vessels. RBCs are essential not only for oxygen transport but also for removing carbon dioxide, a waste product of metabolism, from the body.

Oxygen Percentage in Blood

The body meticulously regulates the percentage of oxygen bound to haemoglobin. Approximately 97% of oxygen in our blood is transported via haemoglobin in the red blood cells. This is why oxygen saturation levels, which measure the percentage of haemoglobin carrying oxygen, are used to assess respiratory efficiency.

In a healthy individual, an oxygen saturation level of about 95-100% is typical. If this drops too low, it can indicate problems with lung function or blood circulation. This high percentage of oxygen carried by haemoglobin underscores how efficient this system is at ensuring tissues receive the oxygen they need.

Transport Mechanism of Oxygen

Oxygen transport in the blood involves both haemoglobin and the red blood cells working together seamlessly. The entire process begins in the lungs, where oxygen enters the bloodstream and binds to haemoglobin in the red blood cells.

The oxygen-rich blood is then pumped throughout the body, delivering oxygen to cells for use in energy production. In the tissues, oxygen is released from haemoglobin, diffusing into cells where it is needed. The red blood cells then pick up carbon dioxide from the tissues and transport it back to the lungs, where it is expelled from the body. This efficient transport mechanism ensures that oxygen supplies remain steady, meeting the tissues' demands at all times.