Co-factor facts for kids

A cofactor is like a special helper molecule for a protein. Proteins are important building blocks and workers in your body. Sometimes, a protein needs a little extra help to do its job properly. That's where cofactors come in! They are not proteins themselves, but they attach to a protein and make sure it can work.

Most of the time, the protein that needs a cofactor is an enzyme. Enzymes are special proteins that speed up chemical reactions in your body. If a cofactor helps an enzyme, it's often called a coenzyme. Think of it like a tool that an enzyme needs to get its work done.

What Are Cofactors?

Cofactors are small chemical compounds. They are not made of the same long chains as proteins. Instead, they are different kinds of molecules that connect to proteins. This connection helps the protein become active. Without its cofactor, a protein might not be able to do its job at all.

How Do Cofactors Help?

Imagine an enzyme as a lock. For the lock to open (or for the enzyme to work), it needs a specific key. The cofactor acts like that key, or sometimes like a part of the lock that makes it work. It helps the enzyme grab onto other molecules or perform its chemical reaction.

Types of Cofactors

Cofactors come in different forms. Some are complex organic molecules, which means they are based on carbon. Others are simple metal ions.

Organic Cofactors: The Vitamin Connection

Many cofactors that are complex organic molecules are called coenzymes. A cool fact is that many of these coenzymes are actually vitamins, or are made from vitamins! This is why vitamins are so important for your health. They help your body's enzymes do their jobs.

Sometimes, a coenzyme is very tightly attached to its protein, almost like it's glued on. This is called a prosthetic group. Other times, the cofactor just connects for a short while and then leaves. This temporary helper is called a cosubstrate.

Metal Cofactors: Tiny Helpers

Besides organic molecules, many metal ions can also act as cofactors. These are tiny bits of metals like iron, copper, or zinc. They fit into specific spots on a protein and help it function. Some proteins even need both an organic cofactor and a metal ion to work!

Here are some examples of metal ions that act as cofactors and the enzymes they help:

Images for kids

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  A simple [Fe₂S₂] cluster containing two iron atoms and two sulfur atoms, coordinated by four protein cysteine residues