Now go to the DNA from the beginning web site and look at the page on DNA structure. Look at the animation and have a go at the problem. Look especially at the work done by Watson and Crick.

There are three main types of nucleic acids.

DNA; deoxyribose nucleic acid

mRNA; messenger ribose nucleic acid

tRNA; transfer ribose nucleic acid

You need to understand the structure of each of these and to understand the dufferences between them.

Deoxyribose nucleic acid

Look at the web site on DNA and make notes on its basic structure. When you have done so try the multiple choice questions on DNA.

Ribose nucleic acid

Messanger RNA (mRNA) and Transfer RNA (tRNA) play a key role in protein synthesis. Make sure that you are certain about the differences in their structure before looking at their role in protein synthesis by looking at the online text book.