1. Protein Synthesis Notes (409-410)

2. Steps of DNA Transcription Making mRNA from DNA 1.Helicase does NOT unzip DNA at the gene of interest 2.RNA polymerase unwinds and matches RNA nucleotide bases to DNA, using one side as a template. 3. The mRNA strand is created. It now compliments the original DNA strand (G-C and A-U). 4. Ligase helps the strand of DNA to close and again. 5. mRNA strand moves out of nucleus to ribosomes, and the DNA zips up.

3. Key Players in Translation rRNA = RNA that makes up a ribosome tRNA = RNA that transfers specific amino acids mRNAmRNA = carries the DNA message; RNA transcribed from DNA Codon = 3 nucleotides in a row on a strand of mRNA that code for an amino acid Anticodon = 3 nucleotides in tRNA that base pair with the codon Amino Acids = monomers of proteins (20 in humans)

4. Steps to Translation Steps to Translation Making proteins from mRNA 1.Ribosomes attach to the “start” codon of mRNA (AUG), signaling the beginning of the protein chain 2.mRNA codons are matched to corresponding tRNA anticodons and appropriate amino acids are strung together. 3.Dehydration synthesis occurs between the amino acids, and they join, making a protein chain with peptide bonds in between 4.Ribosomes detach when they come across a “stop” codon (UAA, UAG, UGA). Protein synthesis is complete.

9. Why do you think RNA uses the “triplet code”? Do the math on your own or with a neighbor.

10. CODON BINGO Fill in the Bingo Card (on page 45) with the 20 different amino acids. –Use your table on page 44 to help –Watch out for repeated amino acids! Wait for your teacher to begin calling out DNA letters to begin playing

11. Translation Activity You and your classmates need to discover the hidden protein in your bag. Follow the instructions in the bag to unlock the mystery protein.

12. What if a single base is changed?

15. Proteins Made up of Carbon, Hydrogen, Oxygen and Nitrogen (and some Sulfur) Proteins are responsible for many reactions

16. Types of Proteins 1. Enzymes = Catalysts that speed up the rate of a chemical reaction –Build up or break down substrate Fit together with its substrate like a “lock” and a “key” –Not used up in the reaction –Work in a very specific biological range –Usually end with “-ase” Hi sweeties, Do you remember me? In addition to what you know. I am a substrate. I am an enzyme. I am going to try to convert you. I am now a product. I am a glucose now. I am a product, too. I am a fructose now. I am completely unchanged, and ready for some more sucrose! I am the active site. The substrate binds to me.

17. Proteins 2. Structural Proteins –Provides mechanical support to cells and tissues 3. Transport Proteins –Transports small ions or molecules 4. Motor Proteins –Enables structures to move

18. Proteins 5. Hormones (signaling proteins) –Carries signals from cell-to-cell –e.g., insulin 6. Storage –Stores small molecules or ions –e.g., iron is stored in the liver in ferritin 7. Other specialized functions –Defense (immune system antibodies), –Receptor proteins (in eyes and muscles to detect stimulus)