What Do Chromsomes Do?

OK, we know that the chromosomes found in the nucleus are DNA, and we know that DNA is the genetic information of a cell, but what does that mean, exactly? What is DNA's job?

DNA's job is to carry the instructions for making proteins. In other words, it tells the cell in what order to connect amino acids to make proteins. But why just protein instructions? Why not carbohydrate instructions or lipid instructions?

The answer is that enzymes are proteins. And if you can make enzymes, the enzymes can them make everything else. The enzymes will run all of the reactions needed to make everything else for a cell.

Human cells contain a lot of DNA. And not all of the DNA carries protein-building instructions. Much of the DNA isn't used at all. The portions of DNA that actually carry instructions for protein synthesis are called genes.

So the chromosomes contain the genes that tell your body's cells how to make the enzymes (and other proteins) they need to function properly.

But you don't go straight from DNA to protein. There's another step in there. Let's take a look.