Nucleic Acids and DNA

In the last lesson you learned about four kinds of organic molecules -- carbohydrates, lipids, proteins, and nucleic acids.    This lesson tells more about nucleic acids and specifically about DNA, which stores genetic information.    Remember that this is just an introduction. 

Nucleic acids are polymers composed of monomer units known as nucleotides. There are a very few different types of nucleotides. The main functions of nucleotides are information storage (DNA), protein synthesis (RNA), and energy transfers (ATP and NAD).

Deoxyribonucleic acid (better known as DNA) is the physical carrier of inheritance for 99% of living organisms. The bases in DNA are C, G, A and T.  

DNA functions in information storage. The English alphabet has 26 letters that can be variously combined to form over 50,000 words. DNA has four letters (C, G, A, and T, the nitrogenous bases) that code for twenty words (the twenty amino acids found in all living things) that can make an infinite variety of sentences (polypeptides). Changes in the sequences of these bases information can alter the meaning of a sentence.

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