AP BIOLOGY

Detailed explanation-1: -Hemoglobin is the protein that carries oxygen and exists within each red blood cell.

Detailed explanation-2: -A protein called haemoglobin in the red blood cells then carries the oxygen around your body. At the same time, carbon dioxide that is dissolved in the blood comes out of the capillaries back into the air sacs, ready to be breathed out.

Detailed explanation-3: -Haemoglobin molecules inside red blood cells pick up and carry the oxygen. These oxygen-rich cells travel in the blood vessels from the lungs to the left side of the heart. The blood is then pumped around the body.

Detailed explanation-4: -After binding with oxygen, the hemoglobin forms a compound called oxyhemoglobin. This oxygen mixed blood is then transported to all cells of the body. When the blood gives away all the oxygen to the cells, it picks up the carbon dioxide from them and transports it back to the heart.