Haem facts for kids

This image shows a heme molecule, like a tiny puzzle piece.

This is another way to see a heme molecule, showing how its atoms are connected.

A haem (pronounced "heem") or heme is a very important part of many living things. Think of it like a special helper molecule. At its heart, it has an iron atom. This iron atom sits inside a large, flat, ring-shaped molecule called a porphyrin.

Even though not all porphyrins have iron, many proteins that contain porphyrins use haem as their helper. These proteins are called haemoproteins. One of the most famous haemoproteins is haemoglobin. This is the red stuff in your blood that carries oxygen all around your body! Haems are also found in many other important proteins that do different jobs in living cells.

What is Haem?

Haem is a special kind of molecule known as a co-factor. A co-factor is like a small assistant that helps a larger protein do its job. Without haem, many proteins wouldn't be able to work correctly.

The Iron Atom

The iron atom in the middle of haem is super important. It's what allows haem to do its main job, which is often to carry or store oxygen. Imagine the iron atom as a tiny magnet that can grab onto oxygen molecules. This is why your blood is red – it's because of the iron in the haem of your haemoglobin!

The Porphyrin Ring

The porphyrin ring is the large, flat, organic (meaning it's made of carbon and other elements) ring that holds the iron atom in place. It's like a special glove that perfectly fits the iron. This ring helps to protect the iron and also helps it to connect with the rest of the protein it's working with.

Where is Haem Found?

Haem is found in many different places in your body and in other living things.

In Blood: Haemoglobin

The most well-known place to find haem is in haemoglobin. Haemoglobin is a protein found in your red blood cells. Its main job is to pick up oxygen in your lungs and deliver it to all the parts of your body that need it. It also helps to carry carbon dioxide back to your lungs to be breathed out. Each haemoglobin molecule has four haem groups, and each haem group can carry one oxygen molecule.

In Muscles: Myoglobin

Another important protein that uses haem is myoglobin. Myoglobin is found in your muscles. It's like a storage locker for oxygen in muscle cells. When your muscles are working hard, they need a lot of oxygen. Myoglobin makes sure there's enough oxygen ready for them to use.

Other Haemoproteins

Haem is also part of many other proteins called enzymes. These enzymes help with important chemical reactions in your body. For example, some haemoproteins help with cellular respiration, which is how your body gets energy from food. Others help to break down harmful substances in your body.

Images for kids

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  This picture shows how oxygen binds to a heme group.

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  Here you can see a heme group from a protein called succinate dehydrogenase. The large clear ball shows where the iron atom is.

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  This image shows how heme is broken down in the body after it's been used.

See also

In Spanish: Hemo para niños