RNA (Leaving Cert Biology): Revision Notes

RNA

RNA (Ribonucleic Acid)

• RNA is a nucleic acid, similar to DNA, but with some key differences.
• RNA contains the sugar ribose. It also has four bases (but one base is different from DNA).
• Adenine (A)
• Guanine (G)
• Cytosine (C)
• Uracil (U)

• RNA bases are complementary to DNA bases.
  • A pairs with U (instead of T).
  • C pairs with G.
• mRNA (messenger RNA) is a single-stranded molecule that carries a copy of the genetic code from DNA in the nucleus to the ribosome, where proteins are made.

	DNA	RNA
Bases	DNA contains A (adenine), T (thymine), C (cytosine), G (guanine)	RNA contains U (uracil) instead of thymine.
Strands	DNA is double-stranded.	RNA is single-stranded.
Location in the Cell	DNA is found in the nucleus.	RNA is found in both the nucleus and the cytoplasm.
Sugar	DNA contains deoxyribose.	RNA contains ribose.