1. Biology: DNA, Transcription, Translation, and Protein Synthesis
Chapters 9 and 10
Biology: DNA, Transcription, Translation, and Protein Synthesis

2. Chapters 9 and 10 Sections 9.1 and 9.2 (whole chapter) Section 10.1
10.2 covers mutations, which we will talk about a little bit with the other information in the chapter. You will be responsible for the information on mutations covered in the slide presentation – not the text.

3. Molecular Genetics
DNA: The Genetic Material
Griffith
Performed the first major experiment that led to the discovery of DNA as the genetic material

4. Concluded that when the S cells were killed, DNA was released
Molecular Genetics
DNA: The Genetic Material
Avery
Identified the molecule that transformed the R strain of bacteria into the S strain
Concluded that when the S cells were killed, DNA was released
R bacteria incorporated this DNA into their cells and changed into S cells.

5. Used radioactive labeling to trace the DNA and protein
Molecular Genetics
DNA: The Genetic Material
Hershey and Chase
Used radioactive labeling to trace the DNA and protein
Concluded that the viral DNA was injected into the cell and provided the genetic information needed to produce new viruses

6. Molecular Genetics

7. DNA Facts The simplest known virus has 5000 paired bases in its DNA.
A single human cell carries about 6.6 billion base pairs in its nuclear DNA.
This is enough information to fill up 600,000 printed pages of 500 words each.

8. DNA: The Genetic Material
Molecular Genetics
DNA: The Genetic Material
DNA Structure
Nucleotides
Consist of a five-carbon sugar, a phosphate group, and a nitrogenous base

9. Chargaff’s rule: C = G and T = A
Molecular Genetics
DNA: The Genetic Material
Chargaff
Chargaff’s rule: C = G and T = A

10. Watson and Crick – indicated DNA was a double helix
Molecular Genetics
DNA: The Genetic Material
Watson and Crick – indicated DNA was a double helix
Built a model of the double helix that conformed to the others’ research
two outside strands consist of alternating
deoxyribose and phosphate
cytosine and guanine bases pair to each
other by three hydrogen bonds
thymine and adenine bases pair to each
other by two hydrogen bonds

11. DNA often is compared to a twisted ladder.
Molecular Genetics
DNA: The Genetic Material
DNA Structure
DNA often is compared to a twisted ladder.
Rails of the ladder are represented by the alternating deoxyribose and phosphate.
The pairs of bases (cytosine–guanine or thymine–adenine) form the steps.

12. DNA: The Genetic Material
Molecular Genetics
DNA: The Genetic Material
Orientation
On the top rail, the strand is said to be oriented 5′ to 3′.
The strand on the bottom runs in the opposite direction and is oriented 3′ to 5′.

13. Semiconservative Replication
Molecular Genetics
Replication of DNA
Semiconservative Replication
Parental strands of DNA separate, serve as templates, and produce DNA molecules that have one strand of parental DNA and
one strand of new DNA.

14. DNA Replication Clip

15. Molecular Genetics
Replication of DNA
Unwinding
DNA helicase, an enzyme, is responsible for unwinding and unzipping the double helix.
RNA primase adds a short segment of RNA, called an RNA primer, on each DNA strand.

16. Molecular Genetics
Replication of DNA
Base pairing
DNA polymerase continues adding appropriate nucleotides to the chain by adding to the 3′ end of the new DNA strand.

17. Molecular Genetics

18. Molecular Genetics
Replication of DNA
One strand is called the leading strand and is elongated as the DNA unwinds.
The other strand of DNA, called the lagging strand, elongates away from the replication fork.

19. DNA ligase links the two sections.
Molecular Genetics
Replication of DNA
Joining
DNA polymerase removes the RNA primer and fills in the place with DNA nucleotides.
DNA ligase links the two sections.

20. Comparing DNA Replication in Eukaryotes and Prokaryotes
Molecular Genetics
Replication of DNA
Comparing DNA Replication in Eukaryotes and Prokaryotes
Eukaryotic DNA unwinds in multiple areas as DNA is replicated.
In prokaryotes, the circular DNA strand is opened at one origin of replication.

21. Contains the sugar ribose and the base uracil
Molecular Genetics
DNA, RNA, and Protein
Central Dogma
RNA
Contains the sugar ribose and the base uracil
Usually is single stranded

22. Associates with proteins to form ribosomes in the cytoplasm
Molecular Genetics
DNA, RNA, and Protein
Messenger RNA (mRNA)
Long strands of RNA nucleotides that are formed complementary to one strand of DNA
Ribosomal RNA (rRNA)
Associates with proteins to form ribosomes in the cytoplasm
Transfer RNA (tRNA)
Smaller segments of RNA nucleotides that transport amino acids to the ribosome

23. Molecular Genetics
DNA, RNA, and Protein

24. Molecular Genetics

25. DNA is unzipped in the nucleus and RNA
Molecular Genetics
DNA, RNA, and Protein
Transcription
Through transcription, the DNA code is transferred to mRNA in the nucleus.
DNA is unzipped in the nucleus and RNA
polymerase binds to a specific section where an
mRNA will be synthesized.

26. Molecular Genetics

27. Intervening sequences are called introns.
Molecular Genetics
DNA, RNA, and Protein
RNA Processing
The code on the DNA is interrupted periodically by sequences that are not in the final mRNA.
Intervening sequences are called introns.
Remaining pieces of DNA that serve as the coding sequences are called exons.
DNA and Genes

28. The three-base code in DNA or mRNA is called a codon.
Molecular Genetics
DNA, RNA, and Protein
The Code
Experiments during the 1960s demonstrated that the DNA code was a three-base code.
The three-base code in DNA or mRNA is called a codon.

29. Each anticodon is complementary to a codon on the mRNA.
Molecular Genetics
DNA, RNA, and Protein
Translation
In translation, tRNA molecules act as the interpreters of the mRNA codon sequence.
At the middle of the folded strand, there is a three-base coding sequence called the anticodon.
Each anticodon is complementary to a codon on the mRNA.

30. DNA, RNA, and Protein Molecular Genetics Visualizing Transcription
and Translation

31. RNA, Transcription, Translation

32. The Genetic Code

33. Eukaryote Gene Regulation
Molecular Genetics
Gene Regulation and Mutation
Eukaryote Gene Regulation
Controlling transcription
Transcription factors ensure that a gene is used at the right time and that proteins are made in the right amounts
The complex structure of eukaryotic DNA also regulates transcription.

34. A permanent change that occurs in a cell’s DNA is called a mutation.
Molecular Genetics
Gene Regulation and Mutation
Mutations
A permanent change that occurs in a cell’s DNA is called a mutation.
Types of mutations
Point mutation
Insertion
Deletion

35. Gene Regulation and Mutation
Molecular Genetics
Gene Regulation and Mutation

36. Protein Folding and Stability
Molecular Genetics
Gene Regulation and Mutation
Protein Folding and Stability
Substitutions also can lead to genetic disorders.
Can change both the folding and stability of the protein

37. Can occur spontaneously
Molecular Genetics
Gene Regulation and Mutation
Causes of Mutation
Can occur spontaneously
Chemicals and radiation also can damage DNA.
High-energy forms of radiation, such as X rays and gamma rays, are highly mutagenic.