Protein Synthesis

One Gene – One Enzyme

Protein Synthesis

Transcription DNA  mRNA Occurs in the nucleus Translation mRNA  tRNA  AA Occurs at the ribosome

Triplets (Codons)

Genetic Code

Transcription

Initiation Promoter TATA Box Initiation Site Transcription factor RNA Polymerase AUG

Elongation RNA Polymerase Adds nucleotides to the 3’ end

Termination Proceeds until RNA polymerase transcribes a terminator sequence UAA UAG UGA

RNA Processing 5’ guanine cap 3” Poly (A) tail

RNA Splicing Introns Exons

Spliceosomes snRNPs Small nuclear ribonucleoproteins

Introns???? Regulation One gene can code for alternate polypeptides Evolution Domains – structural and functional regions

Translation

tRNA

Aminoacyl- tRNA Synthetase

Ribosomes Small subunit Large subunit P site (peptidyl-tRNA) A site (Aminoacyl-tRNA) E site (Exit site)

Initiation

Elongation

Termination

Polyribosomes

Point Mutation

Base Pair Insertion or Deletion Frameshift Missense – new AA Nonsense – stop

Point Mutation Base Pair Substitution