RNA and Protein Synthesis

1. RNA and Protein Synthesis Unit 4B

2. Vocabulary Review Ribosome — makes proteins DNA polymerase – enzyme that puts together DNA Amino acid – building blocks (monomers) of proteins Polypeptide — another name for proteins Genes — sections of DNA that code for something

3. What is RNA? RNA: Ribonucleic Acid Usually single-stranded Monomers are nucleotides (like DNA) Contains base, ribose (sugar), and one phosphate Bases: A, U, C, G U = Uracil

4. 3 Types of RNA rRNA: Ribosomal RNA—makes up ribosome mRNA: Messenger RNA—in the nucleus The messenger from DNA to rest of the cell AKA: codon tRNA: Transfer RNA—in the cytoplasm Transfers amino acids to the ribosome to make proteins AKA: anticodon

5. PROCESS – Protein Synthesis DNA  RNA  Protein Cell Components: Membrane, cytoplasm, etc. Process 1- Transcription Process 2- Translation RNA Proteins DNA Enzymes: Catalyze reactions Process - Replication DNA

6. Protein Synthesis Making proteins 2 main steps: Transcription— DNA gives the instructions on how to make a specific protein to mRNA(messenger) Location: nucleus Translation— Ribosome reads the mRNA and signals tRNA’s to bring the appropriate amino acids to the ribosome in order to produce the protein Location: ribosome

7. TRANSCRIPTION LOCATION: NUCLEUS (because DNA cannot leave the nucleus!) Purpose: mRNA to copy the instructions for making a specific protein from DNA RNA polymerase—an enzyme that reads one DNA strand to make a mRNA strand Just like DNA polymerase, RNA polymerase bonds new nucleotides to form mRNA. Except A = U, C = G

8. TRANSCRIPTION DNA  mRNA

9. TRANSCRIPTION Cont’d RNA polymerase binds nucleotides that are complimentary to the DNA’s sequence. There is a gene on DNA that codes for RNA polymerase to stop

10. TRANSCRIPTION Adenine (DNA and RNA) Cystosine (DNA and RNA) Guanine(DNA and RNA) Thymine (DNA only) Uracil (RNA only) RNApolymerase DNA RNA

11. http://www-class.unl.edu/biochem/gp2/m_biology/animation/gene/gene_a2.htmlhttp://www-class.unl.edu/biochem/gp2/m_biology/animation/gene/gene_a2.html

12. CODONS and ANTICODONS Codon: 3 nucleotide sequence of mRNA Anticodon: 3 nucleotide sequence of tRNA that is complimentary to mRNA Example: AUG-CGG (codons) UAC-GCC (anticodons) • START CODON: AUG • STOP CODONS: UAG, UAA, UGA

14. TRANSLATION LOCATION: RIBOSOME Purpose: make a protein mRNA is read by ribosome Ribosome “translates” message (mRNA) to protein tRNA brings corresponding amino acid to ribosome Ribosome bonds amino acids together (peptide bonds) tRNA

15. TRANSLATION (Cont’d) When the amino acid chain lengthens, this is called elongation. Translation stops when the ribosome reads a stop codon (UAG, UAA, UGA)

16. TRANSLATION

17. TRANSLATION

18. http://www-class.unl.edu/biochem/gp2/m_biology/animation/gene/gene_a3.htmlhttp://www-class.unl.edu/biochem/gp2/m_biology/animation/gene/gene_a3.html http://www.youtube.com/watch?v=983lhh20rGY

19. What is a mutation?? • Change in a sequence of DNA

20. How are mutations good, bad, or equal? • Good-change in DNA sequence that leads to better protein production, increasing the organisms chance of survival. • Ex: camouflage • Bad- change in DNA sequence that leads to the wrong protein formed, decreasing the organisms survival • Ex: genetic diseases such as sickle anemia • Equal- change in DNA sequence that produces the same correct protein.