Nature's incredible code

Biotechnologists who work with proteins have an easier job. Every single cell contains thousands of different proteins that all work together to keep the cell alive. In contrast to cakes, the language of the recipes for such proteins is universal. In fact, every cell in all life on Earth uses exactly the same language in their protein recipes. That is extremely practical, for example, when a biotechnologist wants a bacteria cell to make a human protein. She doesn't need to translate the recipe!

Naturally, protein recipes are not written down on paper. Bacteria cannot read Norwegian, English or any other human language. However, they can read another language, that is, the language of DNA. That is the language that our DNA molecules use. DNA molecules consist of just four chemicals, and we have given them names: A, T, C and G. Using them allows us to make recipes for an endless number of proteins. The letters are put together by following a code known as the genetic code.

Jellymen taste good. They are also a great help for anyone who wants to understand how the genetic code works. Just as DNA molecules have four letters, jellymen are made in four colours: green, red, orange and yellow.

You will need:

• 1 bag of jellymen (Please note that the jellyladies don't work as well)
• Toothpicks that are pointed on both ends, also called cocktail toothpicks

Method:

1. Find a word that has 3 to 5 letters, for example, DNA.

2. This table shows the jellyman code. The rules are:

• Each letter in the alphabet is represented by three jellymen. One to the left, one in the middle and one to the right.
• As regards the third and final jellyman in every code, the one to the right, you can choose between two colours and still code the same letter.
• There are also some jellyman combinations that code full stops, question marks and exclamation marks.

As an example, I'm going to write the word T O E using the jellyman code:

3. Now put three and three jellymen out on the table so they code the word you have chosen.

4. Then put the jellymen together with toothpicks in the right order like this:

5. This is exactly the same way the four chemical letters in a DNA molecule are combined by what are called 'chemical bonds'. But this kind of thread is not very strong. In nature, these rows of DNA letters are tied together by a second thread. So to build a model of a proper DNA molecule, you will need twice as many jellymen.

6. Put a new row of jellymen beside the ones you already made. But now you have to follow a rule (you'll find out why at the end). Put Mr. Orange above Mr Green, and Mr Yellow above Mr Red.

7. Then link them all together with toothpicks like this:

8. Check that all the toothpicks are attached firmly. Lift up the model and turn it carefully in a spiral like a winding staircase.

9. Congratulations! Now you have built a model of a DNA molecule that represents a word. Since you know the jellyman code, you can also read what it says. In just about the same way, nature uses the four DNA letters to describe how all life on Earth should be made. Now you can take your DNA molecule apart and eat it. If you want to understand a bit more about how the genetic code works, you can keep reading while you eat.

Just as words are made of letters, proteins are made of amino acids. While the jellyman code contains 26 letters, there are 20 amino acids in the genetic code. So instead of putting jellymen together three and three, the genetic code puts together the DNA letters A, T, C and G three and three. This lets the cells know which amino acids to put together to build a protein. The recipe for such a protein is called a gene.

Some codes code the same amino acid. In fact, some amino acids have as many as six different codes. That may seem like a waste, but it is actually very smart. You see, sometimes errors occur in DNA molecules and one DNA letter gets mixed up with another one, but there is a certain chance that the new code will still code the same amino acid and the protein will nonetheless be right. Throughout history, many people have managed to avoid getting sick even though their DNA has been damaged. If proteins are in the wrong order, it can result in serious diseases, for example, cancer.

P.S. Maybe you wondered why you had to place an orange jellyman above a green one and a yellow man above a red one? It is because nature follows a similar rule. Only a T can be over an A, and only a G can be over a C!