Transcription and Translation part 2.ppt
- 1. DIRECTION: FILL THE MISSING LETTER TO FIND THE HIDDEN WORD. WHY DO YOU FILL ME UP!
- 2. Why Do You Fill Me Up!
- 3. Why Do You Fill Me Up!
- 4. Why Do You Fill Me Up!
- 6. DNA Replication Three main proteins: Helicase The proteins that separate the two original DNA strand. Polymerase brings in new nucleotides to form new DNA Ligase zips the new DNA back together
- 7. DNA Replication Why is DNA Replication important? ď The important idea is that an exact duplication of the DNA message is required, so that each new cell in the body has the same set of genetic instructions as the cells that preceded it. ď This also insures that every new generation of individuals has the same genetic information as his/her parents.
- 8. ďIn transcription the DNA message is converted into an RNA molecule. ďIn translation the RNA message is used to assemble amino acids into a protein chain. Protein synthesis involves two processes: transcription and translation.
- 10. RNA ď RNA is also a nucleic acid, called ribonucleic acid ď It only has one strand (DNA has two) ď It contains the sugar ribose instead of deoxyribose ď It has the nitrogenous base URACIL (U) instead of thymine (T)
- 11. There are THREE types of RNA ď Messenger RNA (mRNA) ďĄ Long strands of RNA nucleotides that are formed complementary to one strand of DNA ď Transfer RNA (tRNA) ďĄ translates the mRNA codons into the correct amino acids ď Ribosomal RNA (rRNA) ďĄ Associates with proteins to form ribosomes in the cytoplasm
- 13. TRANSCRIPTION (the first step in protein synthesis) ď§ Through transcription, the DNA code is transferred to mRNA in the nucleus. ď§ DNA is unzipped in the nucleus and RNA polymerase binds to a specific section where a mRNA will be synthesized
- 14. Changing nucleic acids into amino acids ď§ The three-base code in DNA or mRNA is called a codon. ď§ They are always coded in threes ď§ Each triplet code corresponds with one amino acid ď§ This is where TRANSLATION begins
- 15. TRANSLATION (the last step in protein synthesis) ď§ Translation begins when mRNA binds to the RIBOSOME in the cell. ď§ In translation, tRNA molecules act as the interpreters of the mRNA codon sequence. ď§ At the middle of the folded strand, there is a three-base coding sequence in the tRNA called the anticodon. ď§ Each anticodon is complementary to a codon on the mRNA.
- 16. ď When the genetic message is copied to make mRNA, the message contains unwanted base sequences. ď The âjunkâ sequences (called introns) are removed from the message and the remaining sequences (exons) are linked together to produce a sequence of codons that will translate into a polypeptide. ď This process occurs before the message leaves the nucleus.
- 17. The role of Ribosomes
- 18. The Role of Ribosomes ďThe third type of RNA is ribosomal RNA (rRNA). Ribosomes are made of RNA and PROTEIN. ďThey are the âdecodingâ units of the cell. (Sites of protein synthesis)
- 19. The Role of Ribosomes ďThey are consist of two major components â the small ribosomal subunit which reads the RNA, and the large subunit which joins amino acids to form a polypeptide chain. ďThey have binding sites for both tRNA and mRNA molecules.
- 20. STAGES OF TRANSLATION 1. INITIATION - In this stage of translation, the ribosome sandwiches the mRNA between its small and large subunit to be translated. The first codon that will be read is AUG that is called the start codon, and consequently codes for the amino acid methionine.
- 22. STAGES OF TRANSLATION 2. ELONGATION - the second stage in translation where the amino acid chain gets longer. In this stage, messenger RNA reads one codon at a time.
- 24. STAGES OF TRANSLATION 3. Termination - the last stage of translation. It is where the finished polypeptide is released.
- 25. TERMINATION starts when a stop codon (UAG, UAA, or UGA) is read by the ribosome, activating a series of events that stop translation and disassemble the subunits of the ribosomal RNA.
- 27. ACTIVITY CODING RIN TAYO SA HULI âŞâŞâŞ