1 / 16

Translation

Translation. Purpose: Translation is the process by which proteins are made Location: On the ribosome. About Proteins. Polypeptide chain Composed of amino acids held together by peptide bonds. Met. Val. Phe. Gly. Tyr. Amino Acids. About Proteins. Polypeptide chain

jayden
Télécharger la présentation

Translation

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Translation

  2. Purpose: Translation is the process by which proteins are made • Location: On the ribosome

  3. About Proteins • Polypeptide chain • Composed of amino acids held together by peptide bonds. Met Val Phe Gly Tyr Amino Acids

  4. About Proteins • Polypeptide chain • Composed of amino acids held together by peptide bonds. Met Val Phe Gly Tyr Peptide Bonds

  5. The Genetic Code • The mRNA is read in sets of three nucleotides = CODONS • The code always begins with a “Start” codon = AUG (methionine) • The code ends with one of three “Stop” codons (UAA, UAG, UGA) which do not code for an amino acid • ALL organisms use the same amino acids and the same genetic code

  6. Reading codons:

  7. The Ribosome • Consists of two subunits – a large subunit and a small subunit • The two subunits join together to read the mRNA • Has three binding sites for tRNA – A (1st), P (2nd) and E (3rd)

  8. Translation • Before translation can occur, mRNA must be transcribed from the DNA in the nucleus • The mRNA transcript is then processed • poly-A tail • methylated cap • Introns removed and exon spliced together

  9. Translation - Initiation • Initiation • An initiator tRNA is loaded onto the small ribosome subunit • The small ribosome subunit attaches to the 5’ end of the mRNA • The small ribosome subunit travels along the mRNA looking for a START codon

  10. Translation – Initiation (cont.) - When a START codon is encountered, the large ribosome subunit attaches to the small subunit - Initiation Complex – formed when the two ribosome subunits attach to the mRNA

  11. Translation - Elongation 2. Elongation: -The mRNA molecule moves between the ribosome subunits. • The mRNA is read and anti-condons on tRNA are matched with codons on mRNA • Amino acids are placed in the correct sequence

  12. Translation – Elongation (cont.) • Enzymes catalyze the formation of peptide bonds between the amino acids

  13. Translation - Termination 3. Termination: - When a stop codon is reached (UAA, UAG, UGA) the ribosome ends the translation. • Stop codons do not code for amino acids

  14. Translation – Termination (cont.) Release factors (proteins) bind to the ribosome and trigger enzyme activity that detaches the mRNA and the polypeptide chain from the ribosome http://www.biologie.uni-hamburg.de/b-online/library/biology107/bi107vc/fa99/terry/images/tlterman.gif

  15. The Central Dogma

More Related