1. Protein Synthesis Making Proteins from DNA

2. DNA & the Nucleus DNA cannot leave the nucleus! So how can we get the information for making proteins out of the nucleus?

3. What is RNA? Ribonucleic acid –A nucleic acid Made up of repeating nucleotides –Backbone Sugar = Ribose Phosphate –Nitrogen bases Adenine Uracil Cytocine Guanine

4. Nitrogenous Base Pairs Adenine pairs with Uracil –A-U Cytosine pairs with Guanine –C-G

5. Differences between DNA & RNA Different Sugars –DNA = deoxyribose –RNA = ribose Different Nitrogen Base Pairs –DNA = thymine –RNA = uracil Single (RNA).vs Double (DNA) Stranded

6. Types of RNA Messenger RNA (mRNA) –Single chain that carries genetic information from DNA in nucleus to the cytosol Transfer RNA (tRNA) –Single chain of abt 80 nucleotides folded into a cross shape that binds amino acids together Ribosomal RNA (rRNA) –RNA in globular form. It makes up the ribosomes where proteins are made

7. TRANSCRIPTION Process where genetic information is copied from DNA into RNA RNA Polymerase binds to promoters and makes RNA copies of a specific sequence of DNA

8. PROTEIN SYNTHESIS Is the production of proteins Remember proteins are made up of polypeptides Polypeptides are sequences of amino acids linked together by peptide bonds

9. Amino Acids There are 20 different amino acids Proteins are made of specific sequences of these 20 amino acids The sequence determines how the proteins twist and fold into a 3-D shape

10. Codons A combination of 3 mRNA nucleotides Codes for a specific amino acid Important Codons –Start codon = AUG –Stop codons = UAA, UAG, or UGA

12. TRANSLATION Assembling polypeptides from info encoded in mRNA mRNA leaves the nucleus and goes to a ribosome in the cytosol where protein synthesis happens

13. tRNA & Anti-Codons tRNA transports amino acids that are in the cytosol to the ribosome tRNA has a section that carries an anti-codon –Anti-codon is complementary to the corresponding mRNA

14. Protein Assembly Begins with start codon AUG tRNA anti-codon is UAC, which is the amino acid methionine Ribosome moves along mRNA to the next codon, the anti-codon binds to the codon and the new amino acid attaches to the first amino acid forming a polypeptide chain until a stop codon occurs