Why is blood red

Red blood cells contain a molecule that gives them their distinctive color. Red blood cells contain a molecule called hemoglobin, which binds and transports oxygen through our bodies.

Hemoglobin is made up of four protein chains that each bind an additional ring-shaped chemical structure called heme. Our red blood cells are red because of the heme groups in hemoglobin.

In turn, our blood is red because of the millions of red blood cells that it contains. Here, Dr. The protein chains in the hemoglobin molecule in red blood cells are encoded by our genes. Mutations in the globin genes can cause diseases such as thalassemia and sickle cell disease. In order to bind oxygen, each protein chain binds to one heme group, allowing a maximum of four oxygen molecules to bind per one hemoglobin molecule. The iron makes heme look red-brown. But what if the iron is swapped for a different metal?

The immune system helps the body defend itself against infection. Different types of WBCs fight germs, such as bacteria and viruses. Some types of WBCs make antibodies, which are special proteins that recognize foreign materials and help the body get rid of them. There are several types of WBCs, and their life spans vary from hours to years. New cells are constantly being formed — some in the bone marrow and some in other parts of the body such as the spleen, thymus, and lymph nodes.

The white blood cell count the number of cells in a given amount of blood in someone with an infection often is higher than usual because more WBCs are being made or are entering the bloodstream to battle the infection. Platelets: Platelets also called thrombocytes, say: THROM-buh-sytes are tiny oval-shaped cells that help in the clotting process. When a blood vessel breaks, platelets gather in the area and help seal off the leak.

Platelets work with proteins called clotting factors to control bleeding inside our bodies and on our skin. Platelets survive only about 9 days in the bloodstream and are constantly being replaced by new platelets made by the bone marrow. With each heartbeat, the heart pumps blood throughout our bodies, carrying oxygen to every cell.

After delivering the oxygen, the blood returns to the heart. Iron is a pure and very common metal. In animals including humans, iron has the very special job of being able to join to — and then deliver — oxygen around to every part of the body. We breathe air into our lungs, we take the oxygen out of that air and it is absorbed into our bloodstream for the iron to carry it off to get to work.

When blood is full of oxygen and on its way around your body, it is bright red. It looks blue. No matter how blue it looks, however, the blood pumping beneath the skin is still red.

Light we see is made up of a range of colours, even though we see it mostly as white. More of the blue part of light is reflected back to your eyes. The deeper the blood vessel below your skin, the bluer it looks. When hemoglobin is carrying a lot of oxygen like when just leaving the lungs , blood is bright red.

When most of the oxygen has been released to the body, blood is dark red. Therefore, contrary to popular belief, blood is never blue. Veins under light colored skin only look blue because the skin changes the optical properties of the light that passes through the skin.

In other words, skin changes the way light is reflected from the blood and we perceive that as being a different color. Why is blood red?