Nucleic acids

Nucleic acids are Examples of information molecules



The nucleic acid deoxyribonucleic acid (DNA) is the genetic material in all cellular organisms

  • it is transmitted from parents to offspring, and it contains information needed to specify the amino acid sequence of all the proteins synthesized in an organism

The nucleic acid ribonucleic acid (RNA) has multiple functions

  • Is a key player in protein synthesis and the regulation of gene expression


DNA and RNA are long molecules consisting of nucleotides bonded covalently one to the next:

- A nucleotide is composed of three components:

  • A 5 carbon sugar

  • Nitrogen-containing compound called a base

  • One or more phosphate groups


The sugar in RNA is ribose

The sugar in DNA if deoxyribose

  • The sugars differ in that ribose has a hydroxyl (OH) group on the second carbon

  • Where as deoxyribose has a hydrogen atom at this position


The bases are built from nitrogen-containing rings and there are two types:

-Pyrimidine bases have a single ring and include:

  1. Cytosine (C)

  2. Thymine (T)

  3. Uracil (U)

- Purine bases have double rings and include:

  1. Guanine (G)

  2. Adenine (A)



Phosphodiester bond: A bond that forms when a phosphate groups in one nucleotide is covalently joined to the sugar unit in another nucle, they are relatively stable and form the backbone of a DNA strand

  • In DNA and RNA each adjacent pair of nucleotides is connected by a phosphodiester bond

  • Involves the formation and release of a water molecule