EVERYDAY SCIENCE

Detailed explanation-1: -Share on Pinterest It is a myth that deoxygenated blood is blue; all blood in the human body is red. Human blood contains hemoglobin, which is a complex protein molecule in red blood cells. Hemoglobin contains iron. The iron reacts with oxygen, giving blood its red color.

Detailed explanation-2: -Human blood is red because hemoglobin, which is carried in the blood and functions to transport oxygen, is iron-rich and red in color. Octopuses and horseshoe crabs have blue blood. This is because the protein transporting oxygen in their blood, hemocyanin, is actually blue.

Detailed explanation-3: -Blood that has been oxygenated (mostly flowing through the arteries) is bright red and blood that has lost its oxygen (mostly flowing through the veins) is dark red. Anyone who has donated blood or had their blood drawn by a nurse can attest that deoxygenated blood is dark red and not blue.

Detailed explanation-4: -Blood is red because of the hemoglobin inside our red blood cells(which is present in our blood). Hemoglobin is a protein that forms a complex with iron molecules and together they transport oxygen molecules throughout the body.