DNA

• Nucleotide - structural unit of nucleic acids; contains a phosphate group, a pentose (5-carbon sugar) and a nitrogenous base.
• DNA (Deoxyribonucleic Acid) - double stranded, contains deoxyribose as the pentose sugar, contains: Adenine (A), Guanine (G), Cytosine (C), and Thymine (T) as bases.
• RNA (Ribonucleic Acid) - single stranded, contains ribose as the pentose sugar, contains: Adenine (A), Guanine (G), Cytosine (C), and Uracil (U) as bases.
• DNA -  It stores instructions for making other large molucules called proteins.
• Types of RNA

  mRNA (messenger) - copies the instruction from the DNA in the nucleus

  rRNA (ribosomal) - forms the structural backbone of ribosomes, facilitates the catalytic reactions necessary for peptide bond formation, and provides binding sites for mRNA and tRNA

  tRNA (transfer) - picks up specific amino acid from cytoplasm and carries it to the site. Attaches itself to ribosome in accordance with sequence specified by mRNA.