DNA, RNA, and Protein

1. DNA, RNA, and Protein

2. Scientist that help discover DNA • Griffith • First major experiment that led to discovery of DNA as genetic material • He found that two stands of bacteria could transform or change into the other form

3. Scientist that help discover DNA • Rosalind Franklin • Used X-ray diffraction to photograph of DNA which showed the double helix- twisted ladder.

4. Scientist that help discover DNA • Chargaff • Anaylzed the amount of adenine, guanine, thymine, and cytosine in DNA of different species • Chargaff’s rule C = G and T = A

5. Scientist that help discover DNA • Watson and Crick • Using Franklin’s and Chargaff’s data they were able to build a model of DNA

6. Structure of DNA • Nucleotide- base building block of DNA made of three parts • Phosphate • Sugar • Nitrogenous base

7. Structure of DNA • The phosphate groups in DNA create a negative charge, and attaches to positive charge of histone proteins and forms a nucleosome

8. DNA Replication

9. DNA Replication • Semiconservative replication- parental strands of DNA separate and serve as templates. Then one new strand is produced that complementary to the parent strand.

11. Background • Enzyme- protein that speeds up a biological reaction by lowering the activation energy need to start the reaction

12. Process of DNA Replication • Uncoiling and unzipping of DNA molecule • Enzyme breaks weak Hydrogen Bond between bases

13. Helicase

14. DNA Replication 2. One side (strand) of DNA molecule is a template for making the other side

15. Process of DNA 2. DNA is broken into 2 strands • Leading strand • Lagging strand • Both of the complementary strands must be written 5’ to 3’

16. Leading & Lagging Strand • The complementary strand to the leading strand is written 5’ to 3’ as one continuous strand • While the complementary strand is written 5’ to 3’ in sections called okazaki fragments.

17. DNA Replication 3. The enzyme DNA polymerase catalyzes the addition of the complementary nucleotides to the new DNA strand. DNA Polymerase Helicase

18. According to Chargaff’s rule what should the DNA polymerase fill in? DNA Polymerase 3’ 5’ A C G T C T C T G C A G A G 5’ 3’

19. RNA • RNA is a nucleic acid similar to DNA but uses the base uracil instead of thymine, and usually a single strand Can you see the difference? Deoxyribose sugar Ribose sugar G A C C A T T C G G T A U C G G U A DNA RNA

20. Three major types of RNA • Messenger RNA (mRNA)- carries genetic information from DNA in the nucleus to direct protein synthesis in the cytoplasm • Ribosomal RNA (rRNA)- associates with protein to form the ribosomes in the cytoplasm • Transfer RNA (tRNA)- transports amino acids to the ribosome

21. How is RNA made? • The synthesis (creation) of mRNA from DNA is know as transcription. • In transcription DNA code is transferred to mRNA, this occurs in the nucleus. RNA is written 5’ to 3’ the same as DNA. • RNA polymerase-an enzyme that regulates RNA synthesis

22. Helicase

23. Transcription RNA Polymerase From what end does the RNA polymerase start transcription at? U C A C U G U C G A U U A G T G A C A G C T A A 5’ 3’

24. RNA processing • Intron- The intervening coding sequence missing from the final mRNA • Exon- The coding sequence that remains in the final mRNA

25. Nucleus 3’ 5’ Intron = Exon =

26. The Code • Codon – The three-base code in DNA or mRNA • There are 64 different combinations of the codon • However only 20 amino acids found in humans

27. Codons

28. Translation • Translation- when mRNA code is read and translated to make a protein • In translation, tRNA molecule acts as the interpreter of the mRNA codon sequence

29. Key players of Translation Amino Acid tRNA Ribosomal Subunits UAC Anticodon AUG UUC UGA mRNA Strand Codon 5’ 3’

30. Cytoplasm UAC AAG AUG UUC UGA 5’

31. DNA Polymerase Replication T C A C T G T C G A T T A G T G A C A G C T A A 5’ 3’ RNA Polymerase Transcription U C A C U G U C G A U U A G T G A C A G C T A A 5’ 3’

32. DNA Polymerase Replication T C A C T G T C G A T T A G T G A C A G C T A A 5’ 3’ RNA Polymerase Transcription U C A C U G U C G A U U A G T G A C A G C T A A 5’ 3’