Patient Care Technician (PCT) AAH Practice Exam

What component of red blood cells is responsible for their color?

1. Chlorophyll

2. Hemoglobin

3. Myoglobin

4. Carotene

The correct answer is: Hemoglobin

Hemoglobin is the component of red blood cells responsible for their distinctive red color. It is a protein that binds to oxygen in the lungs and carries it to the tissues throughout the body. The iron content in hemoglobin is specifically what gives red blood cells their red hue. When oxygen binds to hemoglobin, it forms oxyhemoglobin, which enhances the bright red color seen in oxygenated blood. Chlorophyll, on the other hand, is the pigment found in plants that is responsible for their green color and is not involved in human blood. Myoglobin is similar to hemoglobin but is found in muscle tissue and helps store oxygen there; it does contribute to color but is not involved in the coloration of red blood cells. Carotene is a pigment responsible for the orange color of carrots and certain other vegetables; it has no role in the coloration of blood. Thus, hemoglobin is the correct answer as it directly correlates with the red color of red blood cells.