1. DNA: The Genetic Material
Section 1
Molecular Genetics
DNA: The Genetic Material
DNA Structure
Nucleotides
Consist of a five-carbon sugar, a phosphate group, and a nitrogenous base

2. 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

3. DNA: The Genetic Material
Section 1
Molecular Genetics
DNA: The Genetic Material
Orientation

4. DNA often is compared to a twisted ladder.
Section 1
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.

5. DNA: The Genetic Material
Section 1
Molecular Genetics
DNA: The Genetic Material
Chromosome Structure

6. Transcription Translation
Section 3
Molecular Genetics
DNA, RNA, and Protein
Central Dogma
DNA RNA Proteins
Transcription Translation
Replication

7. 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.

8. Section 2
Molecular Genetics
Replication of DNA
Base pairing

9. Section 2
Molecular Genetics
Replication of DNA
Base pairing

10. Contains the sugar ribose and the base uracil instead of thymine
Section 3
Molecular Genetics
DNA, RNA, and Protein
Central Dogma
RNA
Contains the sugar ribose and the base uracil instead of thymine
Usually is single stranded

11. 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

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

13. 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.

14. The three-base code in DNA or mRNA is called a codon.
Section 3
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.

15. Steps in Translation 1 – Initiation 2 – Elongation 3 – Termination
Section 3
Molecular Genetics
DNA, RNA, and Protein
Steps in Translation
1 – Initiation
2 – Elongation
3 – Termination

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

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

18. Each anticodon is complementary to a codon on the mRNA.
Section 3
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.

19. Section 3
Molecular Genetics

20. Section 3
Molecular Genetics

21. A permanent change that occurs in a cell’s DNA is called a mutation.
Section 4
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

22. Can occur spontaneously
Section 4
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.

23. 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.