1. DNA, RNA, and Protein Synthesis

2. What is DNA? DNA- Deoxyribonucleic Acid Function is to store and transmit hereditary information. In prokaryotes- located in the cytoplasm In eukaryotes- located in the nucleus

3. Structure of DNA DNA is a DOUBLE HELIX- 2 strands wound around each other like a twisted ladder. Strands are held together by weak hydrogen bonds. The building blocks of DNA are called NUCLEOTIDES (made up of 3 things): –Sugar (deoxyribose) –Phosphate –Nitrogen base Make up the backbone or sides of the DNA ladder

5. Four Nitrogen Bases Adenine (A) Thymine (T) Cytosine (C) Guanine (G) Chargaff’s Rules A and T always bond together C and G always bond together

7. Coloring sheet coloring sheet.docx

8. DNA History Frederick Griffith (1928): discovered the molecular nature of genes while studying how bacteria make people sick.

9. History continued Oswald Avery (1944): discovered that DNA is the nucleic acid that stores and transmits the genetic information from one generation to the next.

10. History continued Hershey and Chase Experiment (1952): concluded that the genetic material of bacteriophage (virus that infects a bacteria) is DNA and not protein.

11. Rosalind Franklin (1952): used x-ray diffraction to show that DNA strands are twisted into a helix shape.

12. History continued Watson and Crick (1953): credited with the discovery of DNA as a double helix.

13. Wanna see something… cheek cell- studentcopy.docx

14. DNA Replication- copying the DNA for Cell Division In order for a cell to divide it must make a copy of its chromosomes- the DNA is inside the chromosomes.

16. Process of DNA Replication Enzymes (RNA polymerase) “unzips” molecule of DNA at the hydrogen bonds between the nitrogen bases. Nitrogen bases that are floating around in the nucleus base pair with the unzipped DNA to make 2 new strands: –Each new strand contains an original strand and a new strand of DNA. Example –TACGTT original strand ATGCAA compliment strand

18. Watch This!! Replication We do this for Mitosis!! We can also use this in Meiosis to copy the information to be passed on!

19. Steps of Replication 1. Unwinding of DNA using the enzyme Helicase which unwinds and unzips the H bonds while proteins attach to the strand to keep it unzipped. RNA primase (another enzyme) adds short RNA segments to the DNA strand

20. Step 1

21. Step 2 Base pairing- enzyme DNA polymerase catalyzes the addition of appropriate nucleotides following Chargaff’s rules A – T C – G Okazaki Fragments attach short portions at a time

22. Step 2

23. Step 3 Joining- DNA polymerase reaches the RNA primer and removes the primer and fills in DNA nucleotides and DNA ligase links the sections

24. Step 3

25. PRO VS EU

26. TADA!!! You have a copy of your DNA!!!!

27. So then what? Your cell has to function and go through daily living called its metabolism. To do that we have to make PROTEINS!!!!!!

28. Proteins

29. HOW? RNA- ribonucleic Acid Function of RNA is protein synthesis- to make proteins. Made up of nucleotides –Sugar (ribose), phosphate and a nitrogen base Single stranded instead of double stranded Contains uracil instead of thymine Located in the cytoplasm not the nucleus.

30. 3 types of RNA

31. 3 Types of RNA Messenger RNA (mRNA): goes into the nucleus and reads DNA “code” then carries it to ribosome. Ribosomal RNA (rRNA): makes up the ribosome where proteins are made. Transfer RNA (tRNA): transfers each amino acid to the ribosome as coded by mRNA (from DNA).

32. Protein Synthesis Making proteins using the DNA code. Proteins are enzymes that regulate all chemical processes of living organisms. Proteins are made on RIBOSOMES! Made by joining amino acids into long chains called polypeptides. There are 20 different amino acids.

33. Amino Acids

34. Codons and Amino Acids Codon - genetic code for an amino acid that is 3 letters (nitrogen bases) long. –Example: UCGCACGGU UCG CAC GGU These codons represent the amino acids. There are stop and start codons. AUG means “start.” UAA, UAG, UGA are “stop” codons

36. Steps of Protein Synthesis Step 1- TRANSCRIPTION: decoding DNA into RNA a. Enzyme called RNA polymerase separates DNA into a single strand (serves as the template for mRNA). b. mRNA goes into the nucleus to decode the DNA (uracil subs for thymine). c. mRNA carries the sequence to the ribosome.

37. Transcription

38. Step 2 - Translation Step 2- TRANSLATION: decoding mRNA to make a protein a.tRNA is called the anti-codon. It attaches to the mRNA to pick up the amino acids and carry them to the ribosome. b.The mRNA sequence is used as the code to find amino acids. c. Amino Acids combine until a STOP codon is reached. A protein is made!

39. Translation

40. video Cartoon 3D sentence decoding lab.doc

45. Mutations Mutations – Change in DNA sequence that affects genetic information. Gene Mutations Point Mutations: mutations that affect only one nucleotide. One nucleotide is substituted for another. Frameshift Mutation: deleting a nucleotide or inserting a new nucleotide. This shifts the reading of the Genetic code.

46. Chromosomal Mutations Chromosomal Mutations – changes in the number or structure of chromosome. –Deletion- loss of part of chromosome. Ex: ABC-DEF changes to AC-DEF –Duplication- sequence of chromosome is repeated. Ex: ABC-DEF changes to ABBC-DEF –Inversion – reverse of usual direction –Translocation – one part breaks off and attaches to another.