Chapter 16 Flashcards
DNA
What components make up DNA?
- Phosphate Group
- Hydrogen Bonds
- Nucleotides (Nitrogenous Base)
- Deoxyribose Sugar
How are nucleotides on a single strand held together?
Phosphodiester bond
How many hydrogen bonds hold Thymine and Adenine together?
2 Hydrogen Bonds
How many hydrogen bonds hold Cytosine and Guanine together?
3 Hydrogen Bonds
Pyrimidines
Cytosine, Thymine, Uracil
Purines
Adenine and Guanine
What group is on the 3’ end of a DNA strand?
Phosphate
What group is on the 5’ end of a DNA strand?
Deoxyribose sugar
How are DNA strands laid?
Anti-parallel to each other
How does the sugar differ between DNA and RNA?
RNA has ribose sugar and one more oxygen than deoxyribose sugar.
How does DNA differ from RNA?
- DNA is double stranded, RNA is single stranded
- RNA has Uracil instead of Thymine
- DNA has deoxyribose sugar, instead of ribose
What are the 4 macromolecules?
Carbohydrates, lipids, proteins and nucleic acids
What are the 3 polymers?
- Sugar: Mono/polysaccharides
- Nucleotide monomer
- Proteins: Peptides/ Amino Acids
- Phospholipids: not polymers, amphipathic, membrane bilayer
Gregor Mendel
Hereditable traits: inheritance traits (shape, color, etc)
Thomas Hunt Morgan
Certain traits are linked more tightly than others.
Griffith’s Transforming Principle
Rough strain (non-pathogenic)
Smooth strain (pathogenic)
R strain: mice lived
S strain: mice died
HKS strain: mice lived
HKS + R strain: mice died
Some type of genetic material “transformed” the R strain into the S strain
What are the enzymes that Avery, McLeod, and McCarty used in their experiment?
Protease, DNase, RNase
Avery, McLeod, and McCarty Experiment
To add on to Griffith’s experiment, they added Proteases, DNase, and RNase to the HKS strain to determine which macromolecule is the genetic material. When Proteases and RNase were added to the experiment, the mice still died. But once DNase was added the mice lived. This means that DNA is the genetic material and the material that “transformed” the R strain.
Chargaff’s Rules
G + C = T+A
Rosalind Franklin
X-ray Crystallography. Franklin created a X-ray diffraction photo of DNA that shows that DNA is a double helix. She discovered that there were two outer sugar-phosphate backbones, with the nitrogenous bases paired in the molecule’s interior.
Watson and Crick
Used Rosalind Franklin’s photo to discover that the structure of the DNA is a double helix.
Meselson and Stahl
Meselson and Stahl discovered that DNA replicated in a semi-conservative fashion. Their experiment used radioactive 15N (heavy nitrogen) and 14N in a centrifuge. The bands in the centrifuged test tubes showed that there was 50% of the 14N and 50% of 14N and 15N were in the test tubes.
Hershey-Chase Experiment
Hershey and Chase confirmed that DNA is the genetic material. Radioactive sulfur, 35S, was used to label protein and radioactive phosphorus, 34P, was used to label DNA. They used bacteriophages to study which component entered the cell. Radioactive phosphorus (DNA) was found inside and radioactive sulfur (Protein) was found outside.
