Download
protein synthesis n.
Skip this Video
Loading SlideShow in 5 Seconds..
Protein synthesis PowerPoint Presentation
Download Presentation
Protein synthesis

Protein synthesis

97 Vues Download Presentation
Télécharger la présentation

Protein synthesis

- - - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript

  1. Protein synthesis

  2. Why protein synthesis • Proteins do almost all of the work in the cell (and organism). • Six functions of proteins • Control of the number and type of proteins is critical for maintaining homeostasis. • Understanding protein synthesis allows us to understand the most important homeostatic control system.

  3. scale • Nerve cells rarely undergo mitosis, but require a large number of transport proteins to be produced. • You produce about 1,000,000 red blood cells per minute, each cell is stuffed full of hemoglobin proteins. • Beta cells in the pancreas have to produce insulin in large amounts rapidly when food/drink is taken in.

  4. How is it controlled? • What is found on chromosomes? • What do genes do? • How many genes do we have? • How many different types of proteins are found in your body?

  5. Transcription elongation • RNA Polymerase moves along template strand. • RNA Polymerase makes RNA complementary copy of template strand of DNA. • DNA rewinds pushing off RNA strand

  6. Transcription- termination • RNA Polymerase reaches terminator and falls off. • DNA rewinds pushing the RNA strand completely off.

  7. Translation initiation • tRNA carrying MET joins with mRNA and small ribosome subunit at AUG • Large ribosome subunit joins complex.

  8. Translation elongation • 2nd tRNA brings in next amino acid. • Large ribosome subunit joins amino acids. • Ribosome moves over 1 codon. • 1st tRNA falls off. • Next tRNA comes in.

  9. Translation- termination • When ribosome reaches stop codon, a protein called release factor binds. • Release factor breaks up complex, releasing polypeptide.

  10. RNA processing

  11. RNA processing • Occurs after transcription, before the mRNA leaves the nucleus. • Proteins cut out the introns and put the exons back together. • Exons can be rearranged to produce different proteins from the same gene.

  12. RNA processing • How does the mRNA know where to go? • Proteins add a cap to the beginning of the mRNA. • Cap tells whether mRNA goes to free ribosome in cytoplasm or Rough ER • How many proteins can be made from 1 mRNA strand? • Proteins add a tail to the mRNA, the longer the tail, the more proteins can be made from it.

  13. mutations

  14. Genetic code chart