DNA is composed of a) Sugars b) Nitrogenous bases DNA expanded stands for De-oxyribo Nucleic Acid. The sugars found in DNA are de-oxy ribose. These are sugars with 5 carbons (pentoses). Unlike the sugars in RNA (ribose) which also have 5 carbons, de-oxy ribose lacks a hydroxyl (-OH) group in the second position.This is considered to be one of the reasons DNA is more stable than RNA.The nitrogenous bases found in DNA are purines (adenine and guanine) and pyrmidines (cytosine and thymine).hese are sugars with 5 carbons (pentoses). Unlike the sugars in RNA (ribose) which also have 5 carbons, de-oxy ribose lacks a hydroxyl (-OH) group in the second position. This is considered to be one of the reasons DNA is more stable than RNA.