2. Molecular Genetics Section 1: DNA: The Genetic Material
Section 2: Replication of DNA
Section 3: DNA, RNA, and Protein
Section 4: Gene Regulation and Mutation

3. Section 1
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
Section 1
Molecular Genetics
DNA: The Genetic Material
Avery *
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. Section 1
Molecular Genetics
DNA: The Genetic Material
Hershey and Chase *
Concluded that the viral DNA was injected into the cell and provided the genetic information needed to produce new viruses

6. DNA: The Genetic Material
Section 1
Molecular Genetics
DNA: The Genetic Material
DNA Structure
Nucleotides *

7. Chargaff’s rule: C = G and T = A
Section 1
Molecular Genetics
DNA: The Genetic Material
Chargaff
Chargaff’s rule: C = G and T = A

8. X-ray diffraction data helped solve the structure of DNA
Section 1
Molecular Genetics
DNA: The Genetic Material
X-ray Diffraction
X-ray diffraction data helped solve the structure of DNA
Indicated that DNA was *

9. two outside strands consist of alternating deoxyribose and phosphate
Section 1
Molecular Genetics
DNA: The Genetic Material
Watson and Crick
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

10. DNA often is compared to a *.
Section 1
Molecular Genetics
DNA: The Genetic Material
DNA Structure
DNA often is compared to a *.
Rails of the ladder are represented by the *.
The pairs of bases *.

11. DNA: The Genetic Material
Section 1
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′.

12. DNA: The Genetic Material
Section 1
Molecular Genetics
DNA: The Genetic Material
Chromosome Structure
DNA coils around histones to *.
The chromatin fibers supercoil to form chromosomes that are visible in the metaphase stage of mitosis.

13. Semiconservative Replication
Section 2
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 helicase, an enzyme, is responsible for *
Section 2
Molecular Genetics
Replication of DNA
Unwinding
DNA helicase, an enzyme, is responsible for *
RNA primase adds a short segment of RNA, called *.

15. Base pairing DNA polymerase *. Replication of DNA Section 2
Molecular Genetics
Replication of DNA
Base pairing
DNA polymerase *.

16. *, called Okazaki fragments.
Section 2
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.
*, called Okazaki fragments.

17. DNA polymerase removes the *.
Section 2
Molecular Genetics
Replication of DNA
Joining
DNA polymerase removes the *.
DNA ligase links the two sections.

18. Comparing DNA Replication in Eukaryotes and Prokaryotes
Section 2
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.

19. Central Dogma RNA * * DNA, RNA, and Protein Section 3
Molecular Genetics
DNA, RNA, and Protein
Central Dogma
RNA * *

20. Associates with proteins to form ribosomes in the cytoplasm
Section 3
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

21. Section 3
Molecular Genetics

22. DNA is unzipped in the nucleus and RNA
Section 3
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.

23. Section 3
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.
* are called introns.
* are called exons.
DNA and Genes

24. Section 3
Molecular Genetics
DNA, RNA, and Protein
The Code
Experiments during the 1960s demonstrated that the DNA code was a three-base code.
* is called a codon.

25. In translation, tRNA molecules act as *
Section 3
Molecular Genetics
DNA, RNA, and Protein
Translation
In translation, tRNA molecules act as *
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.

26. Section 3
Molecular Genetics
DNA, RNA, and Protein

27. Section 3
Molecular Genetics
DNA, RNA, and Protein
One Gene—One Enzyme
The Beadle and Tatum experiment showed that one gene codes for one enzyme. We now know that one gene codes for one polypeptide.

28. Prokaryote Gene Regulation
Section 4
Molecular Genetics
Gene Regulation and Mutation
Prokaryote Gene Regulation
Ability of an organism to control which genes are transcribed in response to the environment
An operon is a *.
Operator
Promoter
Regulatory gene
Genes coding for proteins

29. The Trp Operon Gene Regulation and Mutation Section 4
Molecular Genetics
Gene Regulation and Mutation
The Trp Operon

30. The Lac Operon Gene Regulation and Mutation Section 4
Molecular Genetics
Gene Regulation and Mutation
The Lac Operon
Lac-Trp Operon

31. Eukaryote Gene Regulation
Section 4
Molecular Genetics
Gene Regulation and Mutation
Eukaryote Gene Regulation
Controlling transcription
* 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.

32. Hox genes are responsible *
Section 4
Molecular Genetics
Gene Regulation and Mutation
Hox Genes
Hox genes are responsible *

33. RNA Interference RNA interference can *. Gene Regulation and Mutation
Section 4
Molecular Genetics
Gene Regulation and Mutation
RNA Interference
RNA interference can *.

34. Mutations * called a mutation. Types of mutations * * *
Section 4
Molecular Genetics
Gene Regulation and Mutation
Mutations
* called a mutation.
Types of mutations * * *

35. Gene Regulation and Mutation
Section 4
Molecular Genetics
Gene Regulation and Mutation

36. Protein Folding and Stability
Section 4
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
Section 4
Molecular Genetics
Gene Regulation and Mutation
Causes of Mutation
Can occur spontaneously
* also can damage DNA.
High-energy forms of radiation, such *.

38. Body-cell v. Sex-cell Mutation
Section 4
Molecular Genetics
Gene Regulation and Mutation
Body-cell v. Sex-cell Mutation
Somatic cell mutations are not passed on to the next generation.
Mutations that occur in sex cells are passed on to the organism’s offspring and will be present in every cell of the offspring.