1. DNA, RNA and Protein Synthesis
Biology Chapter 10 Notes
DNA, RNA and Protein Synthesis

2. 10.1 and 10.2 – Discovery and Structure of DNA

3. Griffith -

4. Avery – 1940s -

5. Chargaff

6. Hershey and Chase
Hershey and Chase – -

7. Watson and Crick (and Franklin) - 1953

9. Human Genome Project
Attempt to record a complete human genome (all of the A,T,C,G’s). Completed in 2001, but still being interpreted.

10. Dolly the Sheep
The first cloned animal

11. Structure of DNA

12. Structure of DNA
DNA is a double helix structure made up of 2 long chains of repeating nucleotides
A nucleotide has 3 parts: -
-(Adenine, Guanine, Cytosine or Thymine)
The two chains of nucleotides are held together by __________that form between the nitrogenous bases

13. Structure of DNA Some of the bases have 2 rings -purines
and some have 1 ring - pyrimidines
_________: Adenine and Guanine (A and G)
____________: Cytosine and Thymine (C and T)

14. DNA is complementary – if you know one side, you know the other
--Fill out the missing letters
-- Show the H-bonds

15. FUN FACTS!!
The human DNA code is made up of about 3 billion nucleotide pairs (6 billion bases total!!) If the total DNA in one person were laid in a straight line, it would stretch to the sun and back over 600 times (it's 93 million miles from here to the sun). Less than 2% of the DNA in your genome actually codes for proteins

16. Experiments showed that DNA is the hereditary factor that passes on traits
Hershey and Chase
Chargaff
Watson and Crick
Dolly the sheep

17. Used a photograph from Rosalind Franklin to determine the structure of DNA
Hershey and Chase
Chargaff
Watson and Crick
Dolly the sheep

18. How is the structure of DNA best described?
Trapezoidal
Double Helix
Circular
Triple Lutz

19. Always combines with Cytosine…
Adenine
Thymine
Guanine
None of the above

20. Holds the 2 strands of DNA together…
Magic
Covalent bonds between bases
Hydrogen bonds between bases
Ionic bonds between bases

21. What would the genetic code of the complementary DNA strand be
What would the genetic code of the complementary DNA strand be? CGG ATA ACG GAC
CGG ATA ACG GAC
GCC TAT TGC CTG
ATT GCG GTA ACT
TGG CGC TAG CAG

22. Chapter 10.3 – DNA Replication
During what phase of the cell cycle does DNA replication occur?

23. DNA Replication - Enzymes play a key role

24. Steps of DNA Replication
1. The complementary strands ________
Helicases break H-bonds between the 2 strands
Creates replication forks (Prokaryotes have 2, Eukaryotes have thousands at once)
2. Complementary nucleotides are added to each strand
___________“preps” the strand by adding a short segment of RNA
___________adds complementary nucleotides from 5’->3’ on the leading and lagging strands
Gaps are filled in with the help of DNA ligase
3. Enzymes are released and 2 identical DNA molecules result

25. DNA Replication is a “semi-conservative” process

26. Replication in Prokaryotes
-- Replication starts at one replication fork and works its way around the entire loop of DNA
-- -

27. Replication in Eukaryotes
Many replication forks occur at the same time (thousands!!!) on any given chromosome
If only one formed per chromosome, would take 53 days to replicate the largest human chromosome!!!

28. DNA Errors in Replication
Only 1 error occurs in about 1 billion nucleotides (enzymes correct most errors)
Only mutations present in gametes (egg and sperm) can be passed on to offspring -
Some beneficial : HIV resistance

29. When does Replication occur?
G1 Phase
S Phase
G2 Phase
Mitosis

30. What is the Y-shaped region that occurs when the DNA strands separate called?
Template
Helicase
DNA Polymerase
Replication Fork

31. Put the following enzymes in the order in which they are involved in the replication process
RNA Primase – Helicase - DNA Polymerase - Ligase
RNA Primase - DNA Polymerase - Helicase - Ligase
Helicase – RNA Primase - DNA Polymerase – Ligase
Helicase – DNA Polymerase - RNA Primase - Ligase

32. How can we remember the order of enzymes?
Helicase
RNA Primase
DNA Polymerase
Ligase
“Helicopter Rides Don’t Last” ????

33. leading ; lagging lagging ; leading left ; right right ; left
The ________ strand has nucleotides added continuously while the ________ strand has them added in segments called Okazaki fragments
leading ; lagging
lagging ; leading
left ; right
right ; left

34. Leading versus Lagging Strand

35. Nucleotides are always added in a ______ direction
top to bottom
bottom to top
5’  3’
3’  5’

36. Can you meet the Replication Challenge?????

37. Chapter 10.4 – Protein Synthesis
What are proteins?
What are they made of?
Where in the cell are they made?
Today you will learn how they are made!!!

38. Protein Synthesis
DNA contains the instructions for making proteins. The steps in the process are divided into 2 major stages: _____________ and _______________
DNA _________________, so it depends on RNA molecules to transmit the directions for making proteins.

39. THE MAIN IDEA SECTIONS 3 AND 4!

40. Structure of mRNA It is ___________
It has sugar and phosphate as it’s backbone – but the sugar is __________
The four nucleotides that attach to the sugars are
Cytosine
Guanine
Adenine
________

41. There are 3 Types of RNA
_________(messenger RNA) – carries instructions from the DNA in the nucleus out to the cytoplasm
_______(ribosomal RNA) -- part of the structure of ribosomes
________(transfer RNA) -- transfers amino acids to the ribosomes to make proteins

43. Transcription  making RNA
Transcribing the genetic material into an mRNA molecule

44. Steps of Transcription
______________binds to a promoter (a sequence of nucleotides that initiates transcription), causing the DNA to unwind for that gene
RNA polymerase adds complementary nucleotides to ___________(“sense strand”) of the DNA molecule
The RNA polymerase releases the DNA and the new mRNA once it reaches the end of the gene __________= specific sequence of nucleotides)
mRNA can now leave the ________ and take the genetic instructions into the ___________

46. Translation - Making Proteins
Translation = translating the genetic instruction (genetic code) in the mRNA to make a ______
Every 3 adjacent nucleotides in an mRNA molecule is called a codon.
Each codon in mRNA specifies a particular amino acid. Long strings of amino acids = a protein!!

48. Steps in Translation Initiation Elongation Termination
-- The ribosome, mRNA and tRNA (carrying methionine) bind together
Elongation
The tRNA carrying the amino acid corresponding to the next mRNA codon travels to the ribosome
A peptide bond forms between the methionine and the next amino acid
The first tRNA detaches and leaves the methionine behind
Elongation continues and the polypeptide chain grows longer
Termination
A stop codon is reached (it does not code for any amino acid and has no complementary anticodon)
The ribosome releases the mRNA and the newly made protein

49. From DNA -> Protein

50. What’s are the Amino Acids?
DNA sequence: TAC ACU CUU GGC AAC ATT
mRNA codon: __________________________
tRNA anticodon: ___________________________
Amino acids: ___________________________