1. 1
DNA
DNA
CLIP

2. DNA Vocabulary quizzes2
Quiz#2 (Thur)
Messenger RNA
Transfer RNA
Transcription
Translation
Codon
Anti-Codon
Promoter
Intron
Exon
Genetic Code
Amino Acid
Protein
Polypeptide
Mutation
DNA
RNA
Quiz #1 (Tue)
Nucleotide
Base Pairing
Transformation
Deoxyribose
Double Helix
Chromatin
Replication
DNA Polymerase
Helicase
Chromosome
Complementary
DNA

3. UNIT GOALS 3 Distinguish between DNA and RNA.
Explain the role of DNA in storing and transmitting cellular information.
Describe the relationships between changes in DNA and potential appearance of new traits including – alterations during replication, insertions, deletions, substitutions, mutagenic factors, radiation, chemicals.
Examine the use of DNA technology in forensics, medicine and agriculture.

4. DNA 4 Function: Store & Transmit genetic information
Acts as a library or storehouse of informtion.
DNA is located in the nucleus. 4

5. Many People contributed to the discovery of DNA.5

6. Frederick Griffith (Transformation)6
1928
Experiments with Diplococcus pneumonia (bacterium responsible for pneumonia), witnessed a transformation.
These experiments are recognized as the first in a series that lead to the conclusion that DNA is the carrier of genetic information, the genetic material.
DNA is the molecule of inheritance

7. Oswald Avery 7 1944 Repeated Griffith’s experiment
Looking for “what” is being transferred.
Used enzymes to break up carbohydrates, lipids and proteins-transformation still took place.
Used enzymes to break up DNA-transformation did not happen.
Conclusion: DNA is a Nucleic Acid

8. Rosalind Franklin & Maurice Wilkins
1952
Used x-ray diffraction to see DNA.
Conclusions: DNA is twisted like a spiral staircase
Double helix 8

9. 9 Erwin Chargaff Conclusions: 1952 Discovered that the
amount of Adenine = amount Thymine
amount of cytosine = amount of guanine.
True in all organisms tested.
Called Chargaff’s Rule.
Conclusions:
1. amt A is = to amt of T
2. amt C is = to amt of G 9

10. Watson and Crick
1953
“Put it all together”
Developed the structure of DNA that we know today.
Conclusions: Described the complete structure of DNA. 10
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11. 11

12. What we
Know
Now 12

13. Structure of DNA 13 Double Helix. Two stranded
-Twisted ladder or spiral staircase
Two stranded
Held together by hydrogen bonds
Made of four Nucleotides
Phosphate
Base ( Nitrogen)
Sugar 13

14. Structure of DNA 14 Remember: DNA is a nucleic acid.
Nucleic acids are made of nucleotides 14

15. Structure of DNA Nucleotides The sugar is Deoxyribose
Long chain of Nucleotides
There are four nucleotide that make up DNA
Each nucleotide has three parts: (PBS)
The sugar is Deoxyribose
There are four bases
Adenine, Guanine, Cytosine, Thymine 15

16. Sides of the “Ladder” are made up of sugar and phosphate.
4 Bases 14
Adenine
Guanine
Cytosine
Thymine
Sides of the “Ladder” are made up of sugar and phosphate. 16

17. Adenine always pairs with Thymine Cytosine always pairs with Guanine17

18. Would Thymine be able to pair up with Guanine?
NO!! 18

19. 19
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20. 20
The sequence of nucleotides forms the unique genetic information of an organism.

21. Before a cell divides it needs to make a copy of its DNA.
Flashback 21
Before a cell divides it needs to make a copy of its DNA.
(Remember S-phase?)
How does it do that?

22. DNA
REPLICATION
DNA has the unique ability to make an exact copy of itself in a process called Replication. 20 22

23. 23 Chromosome Structure DNA is packed very tightly in the nucleus.
Human nucleus has ~1 meter of DNA!
Smallest human chromosome has 30 million base pairs.

24. 24 A chromosome has DNA and protein-chromatin.
Tiny sections of DNA are called genes 24

25. DNA Replication 25
Before Cell Division, the DNA must be replicated exactly.
Each strand is used to make a new strand.

26. Complementary Strands26
Many enzymes are involved.
Complementary Strands

27. Steps:
The two parent strands are unwound and unzipped with the help of DNA helicases.
Replication Bubble 27

28. Replpication
Bubbles 28

29. Steps:
2. DNA polymerase attaches new nucleotides (base paring) to the parent strands
**Each new strand formed is a complement of one of the original, or parent, strands. 29

30. This process will continue until the entire molecule has been unzipped and replicated.30

31. Semi-conservative replication
DNA replication website
Each new strand formed is a complement of one of the original, or parent strands.
Semi-conservative replication 31

32. When all of the DNA in the chromosomes of the cell have been copied by replication, there are now two copies of the genetic information that will be passed on to new cells during mitosis or to new generations through the process of meiosis. 32
Review Clip

33. DNA stores the information needed by a ribosome to make a protein.
How does the ribosome get the information?
How does the ribosome read the information?
How does it make the protein? 33

34. How a protein is made.
“PROTEIN SYNTHESIS” 34

35. DNA contains the code for all of the cell proteins.35

36. Flashback:
DNA is located in the Nucleus
Proteins are made on the ribosomes.
DNA makes a copy (send a message) called “mRNA” 36

37. Two Steps of Protein Synthesis
2. Translation
1. Transcription
LOCATIONS
Where do the steps take place? 37

38. 1. Transcription: Nucleus
During transcription a “backwards copy” of the DNA is made…the copy is called messenger RNA or mRNA. The mRNA takes the code to the ribosome. 38

39. 39 The section that is copied is called a gene.
1. Transcription: Nucleus
The section that is copied is called a gene.
The gene contains the code for a protein.
“backwards copy” 39

40. DNA vs. RNA Double Stranded AGTC Deoxyribose NEVER! Single Stranded
AGUC
Ribose
YES! 40

41. 2. Translation: Cytoplasm
Once the mRNA copy is made, it can go to the ribosome and be used to make a protein (translated) 41

42. The ribosome reads every 3 letters
2. Translation: Cytoplasm
To have the correct translation of the code, mRNA codons must join with the correct anticodon
of the tRNA.
Ribosome
tRNA anticodon
mRNA codons
The ribosome reads every 3 letters 42

43. 43 2. Translation: Cytoplasm tRNA anticodon mRNA codons
To have the correct translation of the code, mRNA codons must join with the correct anticodon of the tRNA.
tRNA brings the amino acids to the ribosomes
tRNA anticodon
mRNA codons
A codon is a group of 3 nitrogenous bases on an mRNA molecule that carries the code for a specific amino acid.
An anticodon is a set of 3 nitrogenous bases on a tRNA molecule that matches a codon on an mRNA molecule. 43
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44. 44 Remember….Proteins are made out of amino acids.
There are 20 different amino acids.
3 bases code for each amino acid. 44

45. mRNA codons 45

46. In summary:
Messenger RNA (mRNA) carries the message of the genetic code from the DNA in the nucleus to the ribosomes in the cytoplasm. At the ribosomes, the mRNA sequence is translated into a protein in a process known as translation. Transfer RNA (tRNA) transfers the amino acids in the cytoplasm to the ribosomes. The amino acids are lined up in the coded sequence to form a specific protein. 46
Review Clip

47. 47

48. Eukaryotic DNA processing
Sometimes the DNA is cut up before it leaves the nucleus.
Exon - RNA sequences in the primary transcript that are found in the mRNA
Intron - RNA sequences between exons that are removed by splicing 48

49. EOCT Questions Which of the following shows how information is transformed to make a protein? A DNA→RNA→protein B gene→chromosome→protein C cell respiration→ATP→protein D ATP→amino acid→protein 49

50. Information on mRNA is used to make a sequence of amino acids into a protein by which of the following processes?
A replication
B translation
C transcription
D transference 50

51. 51

52. Which of the following is the correct base-pairing rule for DNA?
A A-U; C-G
B A-G; T-C
C A-T; G-C
D A-C; T-G 52