1. Bell Ringer 3.22 1.What is DNA? 2.Why do you think DNA needs to be replicated? 3.DNA  RNA  Proteins (Central Dogma)

2. Review: DNA = d eoxyribo n ucleic a cid DNA replication: how DNA copies itself and produces more DNA molecules. ▫ DNA Helicase attaches to DNA and unzips it ▫ Strands are separated; unpaired bases react with free nucleotides in the nucleus ▫ Free nucleotides attach forming new hydrogen bonds; DNA polymerase connects the new nucleotide strand with sugar-phosphate bonds. DNA nitrogenous bases: ▫ A: adenine ▫ T: thymine ▫ C: cytosine ▫ G: guanine

3. RNA & Transcription Notes

4. RNA R ibo n ucleic a cid Organic compound that uses info from DNA to make proteins DNA never leaves the nucleus.

5. RNA monomer is a nucleotide Phosphate group Ribose sugar Nitrogenous base 4 types: A denine (A) G uanine (G) C ytosine (C) U racil (U) NO THYMINE!

6. DNARNA StructureDouble-stranded (two strands of nucleotides) Single-stranded (one strand of nucleotides) Sugar Nitrogenous BasesThymine (T) Adenine (A) Guanine (G) Cytosine (C) Uracil (U) Adenine (A) Guanine (G) Cytosine (C) DeoxyriboseRibose

7. Three Types of DNA Messenger RNA Transfer RNA Ribosomal RNA

8. 1. Messenger RNA mRNA is a copy of DNA mRNA brings instructions from DNA (in the nucleus) to ribosomes for protein synthesis

9. 2. Transfer RNA tRNA carries an amino acid to a ribosome to help make a protein. The anticodon on the tRNA matches a codon on the mRNA

10. 3. Ribosomal RNA Ribosomes are made of rRNA and protein Ribosome rRNA mRNA

11. Transcription Makes RNA from DNA Steps: 1.Enzymes unzip one gene in DNA 2.Match up RNA nitrogenous bases to one side of a gene on DNA 3.mRNA strand breaks away, DNA joins back together. 4.mRNA moves out of the nucleus into the cytoplasm

12. DNA: GAC AAC TAG TAC RNA:

13. DNA mRNA Cytoplasm of cell Nucleus Transcription happens in the nucleus. An RNA copy of a gene is made. Then, the mRNA that has been made moves out of the nucleus into the cytoplasm. Once in the cytoplasm, the mRNA is used to make a protein.

14. How does mRNA tell the cell what to do? mRNA contains the message that codes for a protein.

15. Translation  Protein Synthesis The process of making proteins Proteins make up EVERYTHING in your body! Ribosomes (made of rRNA) are the site of translation. Remember: proteins are made of amino acids !

16. Process of Translation 1.mRNA moves out of nucleus through a nuclear pore and into the cytoplasm 2.mRNA attaches to a ribosome

17. Process of Translation 3. Transfer RNA (tRNA) brings amino acids to the ribosome to build the protein

18. Process of Translation 4. Protein (chain of amino acids help together by peptide bonds ) detaches from ribosome and goes off to work in the cell. aka polypeptide

19. Genetic Code Codon: group of THREE mRNA nitrogenous bases that code for a specific amino acid. GAA CCG GGU UUU CAC CGU UGA

20. Codon Chart

21. DNA: GTT mRNA: Amino Acid:

22. There are 64 codons that code for 20 amino acids… How is this possible? More than one codon may code for ONE amino acid Example: CGU, CGC, CGA, CGG, AGA, & AGG all code for arg The genetic code is said to be universal because it is the same in almost all organisms. Worm – AUG = methionine Human – AUG = methionine

23. Central Dogma of Molecular Genetics

24. Gene  RNA  Protein DNA Code: CGT CCA CTT mRNA code: Amino acid:

25. Which amino acid sequence can be coded from the DNA sequence CAG TAG CGA? A.Val – Iso – Gly B.Val – Asp – Ala C.Val – Iso – Ala D.Val – Ile – Ala

26. A sugar, a phosphate group, and a nitrogen base from the building blocks of which organic compound? A.Carbohydrates B.Lipids C.Nucleic acids D.Proteins

27. Which relationship is most similar to the relationship below? tRNA : ribosome A. book : publisher B. truck : factory C. key : lock D. baker : pie

28. TOTD What does the central Dogma say?

29. Bell Ringer 3.23 1.Does DNA ever leave the nucleus? 2.How does DNA determine the function of a protein? 3.Compare DNA to RNA. What’s different? What’s the same?

30. Agenda… 1.Bell Ringer 2.Review 3.Stations 4.Finish Replication packet 5.Web Quest  first link skip! 6.Review H/W (due Thursday)