RNA: Structure and Function

What is RNA?

n Ribonucleic Acid

n “Decodes” instructions from DNA codes

Structure

n Made of nucleotides – Sugar (ribose) – Phosphate group

(phosphate + oxygen) – Nitrogen base (A, U,

C, G) n  U = Uracil (no Thymine)

Sounds a lot like DNA?

n How it’s different: – Sugar is ribose – Single stranded – Contains uracil

instead of thymine

3 Types of RNA

1. Messenger RNA (mRNA) – Carry copies of instructions for assembling proteins

3 Types of RNA

2. Ribosomal RNA (rRNA) – Make up ribosomes, where proteins are assembled

3 Types of RNA

3. Transfer RNA (tRNA) – Transfers amino acid to the ribosome as coded by the mRNA

Steps of Protein Synthesis n  1st Step

– Transcription n DNA is transcribed to produce a molecule of mRNA

n  2nd Step – Translation

n  tRNA is translated in to amino acids or proteins

DNA mRNA transcription

Protein translation