1 / 27

Protein Synthesis (to make proteins)

Protein Synthesis (to make proteins). What is Protein Synthesis?. Flow of Genetic Information: DNA RNA Protein DNA holds the code for protein synthesis but cannot leave the nucleus. Protein Synthesis is performed at the ribosomes in the cytoplasm

lanai
Download Presentation

Protein Synthesis (to make proteins)

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. Protein Synthesis (to make proteins)

  2. What is Protein Synthesis? Flow of Genetic Information: DNA RNA Protein DNA holds the code for protein synthesis but cannot leave the nucleus

  3. Protein Synthesis is performed at the ribosomes in the cytoplasm The cell uses RNA to copy the code from DNA and bring it to the ribosomes

  4. RNA – Ribonucelic Acid Nitrogenous Bases a. Adenine b. Cytosine c. Guanined. Uracil Simple Sugar – a ribose rather than a deoxyribose Phosphate Groups

  5. II. Structure a. A nucleic acid backbone b. single strand of nucleotides c. Sugar is ribose d. Contains uracil base instead of thymine

  6. Difference between DNA and RNA • DNA RNA • Double strand single strand • Deoxyribose ribose • Thymine uracil

  7. III. Types of RNA Three types of RNA are used to make proteins a. mRNA – messenger RNA b. rRNA – ribosomal RNA c. tRNA – transfer RNA

  8. IV. mRNA Function A. transcribe DNA code B. take code outside of nucleus to ribosome C. give instructions to ribosome on how to build protein

  9. How does DNA transfer info to RNA? A = U G = C T = A No T’s in RNA

  10. V. tRNA Function • To deliver amino acids to the ribosome as it is building (synthesizing) protein

  11. VI. rRNA Function • where translation of RNA to protein takes place • Ribosomes are made up of protein and ribosomal RNA (rRNA)

  12. Remember: How many different amino acids are there? 20 Look at your notes - What makes each amino acid different from one another? R groups

  13. VIII. The CODE!! • James Watson and Francis Crick, with the help of Rosalind Franklin’s X-ray crystallography images unraveled the structure of DNA: B. The fact that bases paired led directly to a theory of how DNA codes for proteins. It took a few years to determine that the bases spell three-letter “words” called codons

  14. mRNA Codons • 3 letters on mRNA are called codons. These three letter codes are used to determine which Amino Acid is to be placed on the protein. Ex: TAC AUG = Start Codon (Methionine) This is where you begin translation of DNA’s code given to mRNA

  15. See the mRNA codon chart (slime green) • Write the codon for Proline here: • Glycine? • Which amino acid has the most codons? • Which amino acid has the fewest? • Start codon starts each protein • Three codons tell a ribosome to stop making a protein. List them here:

  16. Transcription? - Copying the portion of DNA that carries the code for a protein. http://www.youtube.com/watch?v=ztPkv7wc3yU&feature=related mRNA Synthesis (Transcription begins with a promoter on DNA, site RNA polymerase binds to on DNA to begin transcription). • A mRNA is transcribed (built) using unwound DNA’s code as a template. • RNA nucleotides find their compliment. • RNA Polymerase is the enzyme that brings in the nucleotides

  17. - Completed when reaches terminator sequence on DNA – ending transcription The original strand is used as the template.

  18. Result: The resulting mRNA looks exactly like the template strand of DNA, with one important distinction each T is replace with a U. http://www.youtube.com/watch?v=Jqx4Y0OjWW4&feature=related Where does it go? The RNA releases from DNA and is then edited before leaving the nucleus

  19. Practice Transcription DNA Strand 3 ‘ T A C G A T G C A T C G 5’ RNA Strand 5 ‘ A U G C U A C G U A G C 3’ http://www.youtube.com/watch?v=NjczQKjFcks&feature=related

  20. Translation • The process of interpreting mRNA to build a chain of amino acids that make up a protein. http://www.youtube.com/watch?v=B6O6uRb1D38&feature=related

  21. How does it work? i. mRNA leaves the nucleus and heads to the cytoplasm where the ribosomes are located. Remember: Ribosomes are where translation will occur • Each sequence of nucleotides is a codon (mRNA codon). Each codon codes for a specific amino acid

  22. ii. Amino acids are brought to the ribosome by tRNA. • There are 20 different tRNA molecules, one for each type of amino acid. • tRNA anticodon finds their complimentary codon on mRNA.

  23. Anticodon – 3 letters found to match the mRNA’s codon. • mRNA codon: UAA CGA GGC • tRNA anticodon: AUU GCU CCG

  24. iii. Peptide bonds form between the amino acids forming a polypeptide. iV. Translation stops when a stop codon is reached. Video: http://www.youtube.com/watch?v=41_Ne5mS2ls&feature=related

  25. Video: http://www.youtube.com/watch?v=983lhh20rGY&feature=related

More Related