2. Making Proteins

3. Cell Structure (80% of cell membrane is proteins) Transport Channels Cell Processing Hormones (signals) Enzymes What else?

4. 1. DNA Is the template for making mRNA during transcription 2. RNA mRNA =messenger RNA Makes and takes copy DNA to cytoplasm

5. tRNA = transfer RNA Matches with mRNA on ribosomes Carries Amino Acids rRNA = ribosomal RNA Part of ribosome Reads mRNA Directs tRNA 3. Ribosome Reads mRNA Directs tRNA Creates peptide bonds between AA’s

6. 4. Amino Acids (AA’s) Building blocks of proteins (20 AAs essential) Protein = AA chain = polypeptide chain ORDER MATTERS! AA order determines f(x) of protein

7. http://www.columbia.edu/ cu/biology/courses/c2005/i mages/animtransln.gif

8. TRANSCRIPTION : writing the message DNA  mRNA STEPS: 1. unwind DNA in nucleus with help of enzyme 2. DNA polymerase pairs RNA nucleotides with DNA nucleotides =mRNA * U replaces T in RNA *

9. 3 DNA nucleotides (triplet)   m RNA CODON Codons Start Codon

10. TRANSLATION: mRNA  tRNA  Protein (AA chain) Steps: 1. mRNA leaves nucleus and binds to ribosome 2. tRNA (anticodon) brings the amino acid to the mRNA (codon) on ribosomes

11. 3. Ribosomes move down mRNA to next codon 4. tRNA anticodon brings and attaches next AA with peptide bond 5. tRNA leaves ribosome once AA attached 6. Repeat above steps to add AA until STOP CODON to signal end of protein UAG, UAA, or UGA 7. Polypeptide chain releases from ribosomes

12. 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

13. 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

14. 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.

15. 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.

16. 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

17. 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

18. 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.

19. 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

20. 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

21. 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.

22. DNA : A=T and C=G RNA: A=U and C=G * So, when transcribing DNA into RNA “T” is replaced with “U” Example: Original DNA:ATCG Complementary DNA: TACG Transcription example: Original DNA:ATCG Messenger RNA:UACG (CODON)

23. Translation Example: Messenger RNA:UACG (CODON) Transfer RNA:AUGC (ANTICODON) tRNA brings the AA so they can bond to make protein

24. DNA (triplet) mRNA (codon) tRNA (anti-codon) TAC GGA CCT TAT ACT AUG (start) CCU GGA AUA UGA (stop) UAC GGA CCU UAU ACU

25. Use mRNA codon and use the Universal Genetic Code Chart. AUG (codon) A = 1 st base U = 2 nd base G = 3 rd base