RNA is the nucleic acid that is used to express the genetic instructions within a cell (it is involved in protein synthesis)

• RNA is a single stranded molecule produced from a DNA template (gene) via condensation of nucleotide monomers
  

• The order of the nucleotide monomers is determined by base pairing (the RNA sequence will be complementary to the gene sequence)
  

There are three main types of RNA involved in the the synthesis of proteins:

• Messenger RNA (mRNA) is the transcript copy of the DNA instructions (it encodes the protein sequence) 
  

• Transfer RNA (tRNA) carries the protein subunits (amino acids) to the mRNA transcript
  

• Ribosomal RNA (rRNA) provides the catalytic activity for combining the amino acids according to the mRNA sequence
  

While mRNA is a linear molecule, complementary base pairing can allow tRNA and rRNA to twist and form loops

Types of RNA