Hemoglobin

Hemoglobin is a very special protein that lives inside our red blood cells. Just like how we need food to give us energy, our red blood cells need hemoglobin to carry something very important called oxygen all around our bodies.

Oxygen is like the "Good Guy" who helps us breathe and keeps us alive. When we breathe in air, we breathe in oxygen too. This oxygen needs to be carried to all parts of our body so that it can be used by our cells to do work.

That's where hemoglobin comes in. Hemoglobin is something like a big truck that carries the oxygen from our lungs to the various parts of our body that need it. Once it reaches the right part, it drops off the oxygen like a delivery man dropping off a package.

But that's not all. Hemoglobin has another very special trick up its sleeve. It can also carry something called carbon dioxide (CO2) which is like a "bad guy" that's produced by our body's cells when they do their work.

Once hemoglobin has dropped off the oxygen, it can pick up CO2 and carry it away to our lungs where we breathe it out. So, hemoglobin is like a superhero that helps our body breathe in oxygen and get rid of carbon dioxide so we can stay healthy!