1. Protein Synthesis Who am I? How was I formed? Where’s my mom? A molecular model of the YiiP zinc transporter protein with bound zinc ions (red spheres).

2. Zinc is essential for:  cellular growth  cell differentiation  structural component of proteins and enzymes  involved in myriad of processes, from gene expression to immune function  modulates the activity of chemical messengers in the brain  helps to regulate the release of insulin from pancreatic cells in response to changing blood sugar levels Too much zinc can be toxic and cause:  seizures  deposits of protein plaques in Alzheimer's disease.

3. Protein Synthesis Two Steps: 1.Transcription 2.Translation http://www.youtube.com/watch?v=983lhh20rGY

4. The Central Dogma

5. Protein Synthesis Step 1: Transcription of the Genetic Code

6. http://www-class.unl.edu/biochem/gp2/m_biology/animation/gene/gene_a2.html Transcription Transcription – the information encoded in DNA into a molecule of RNA

7. Transcription Three Types of RNA: Ribosomal RNA (rRNA) Builds ribosomes - the machinary that synthesizing proteins. Messenger RNA (mRNA) Complementary base pair copy of DNA that will be translated into a polypeptide Transfer RNA (tRNA) Carries amino acids to the growing polypeptide. DNA filament

8. Transcription Three Events: 1. Initiation Binds RNA polymerase to DNA strand. Unwinds DNA so that only one side of DNA is copied. 2. Elongation Covalent addition of complementary bases to growing mRNA strand. 3. Termination Recognition of stop codon and release of mRNA strand. Complementary Base Pairs Adenine bonds with Uracil Guanine bonds with Cytosine

9. Transcription

11. Transcription Questions! 1.What is the function of rRNA? To build a ribosome that will synthesize proteins. 2.What is the function of mRNA? To make a complementary base pair copy of DNA 3.What is the function of tRNA? Carry amino acids to the growing polypeptide 4.What are the three steps of transcription? 1. Initiation 2. Elongation 3. Termination

12. Protein Synthesis Step 2: Translation of the Genetic Code

13. Translation http://bcs.whfreeman.com/thelifewire/content/chp12/1202003.html Translation – the process of converting the information encoded in mRNA to a polypeptide

14. Translation Three Events: 1. Initiation Small ribosome subunit binds to mRNA until it encounters a Start codon ( AUG ) Then, the large ribosome subunit binds to the small subunit along with initiator tRNA (methionine) 2. Elongation tRNA brings amino acids to ribosome, complementary tRNA pair with mRNA, and then sequential amino acids are joined together by peptide bonds. 3. Termination Recognition of stop codon and release of mRNA strand.

16. Translation and Transcription Review! http://learn.genetics.utah.edu/content/begin/dna/transcribe /

17. A U G G G C U U A A A G C A G U G C A C G U U This is a molecule of messenger RNA. It was made in the nucleus by transcription from a DNA molecule. mRNA molecule codon

18. A U G G G C U U A A A G C A G U G C A C G U U A ribosome on the rough endoplasmic reticulum attaches to the mRNA molecule. ribosome

19. A U G G G C U U A A A G C A G U G C A C G U U It brings an amino acid to the first three bases (codon) on the mRNA. Amino acid tRNA molecule anticodon U A C A transfer RNA molecule arrives. The three unpaired bases (anticodon) on the tRNA link up with the codon.

20. A U G G G C U U A A A G C A G U G C A C G U U Another tRNA molecule comes into place, bringing a second amino acid. U A C C C G Its anticodon links up with the second codon on the mRNA.

21. A U G G G C U U A A A G C A G U G C A C G U U A peptide bond forms between the two amino acids. Peptide bond C C G U A C

22. A U G G G C U U A A A G C A G U G C A C G U U The first tRNA molecule releases its amino acid and moves off into the cytoplasm. C C G U A C

23. A U G G G C U U A A A G C A G U G C A C G U U C C G The ribosome moves along the mRNA to the next codon.

24. A U G G G C U U A A A G C A G U G C A C G U U Another tRNA molecule brings the next amino acid into place. C C G A A U

25. A U G G G C U U A A A G C A G U G C A C G U U A peptide bond joins the second and third amino acids to form a polypeptide chain. C C G

26. A U G G G C U U A A A G C A G U G C A C G U U The polypeptide chain gets longer. G U C A C G The process continues. This continues until a termination (stop) codon is reached. The polypeptide is then complete.