lecture21 - Processes Affecting Steady-State Protein...

Info iconThis preview shows pages 1–5. Sign up to view the full content.

View Full Document Right Arrow Icon
Processes Affecting Steady-State Protein Concentration Gene DNA Primary Transcript Mature mRNA Protein (inactive) Active Protein (modified) * * * * Transcription Processing Translation Post-Translational Processing mRNA degradation Protein degradation ...or deferred folding
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Protein Synthesis • Requires ~300 different macromolecules (proteins and RNAs) present in thousands of copies per cell Requires ~20,000 ribosomes, 100,000 related factors and enzymes, and 200,000 tRNAs per bacterial cell mRNA is translated using genetic code --triplet code = codons • mRNAs from eucaryotes-- usually monocistronic ribomes enter at 5’ end • procaryotic mRNAs--usually polycistronic internal ribosome binding sites
Background image of page 2
Genetic Code • Assign 1 letter code to amino acids. • Know how to read chart.
Background image of page 3

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Features of Genetic Code Redundant or Degenerate --usually a feature of 3rd position of codon --3rd position referred to as “wobble position” --mRNA can predict protein sequence but protein sequence cannot predict mRNA sequence Start codons = initiation codons • AUG--incorporation of N-formylmethionine (f-met) in procaryotes; incorporation of met in eucaryotes • UUG and GUG--incorporation of f-met if first codon (instead of leu or val) Stop codons = termination codons = nonsense codons • UAA (amber) •UAG (ochre) •UGA (opal)
Background image of page 4
Image of page 5
This is the end of the preview. Sign up to access the rest of the document.

Page1 / 19

lecture21 - Processes Affecting Steady-State Protein...

This preview shows document pages 1 - 5. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online