2.6 Structure Of DNA And RNA Flashcards
Nucleic acids
Polymers of nucleotides.
DNA (deoxyribonucleic acid)
RNA (ribonucleic acid)
A type of macromolecule, long chain of smaller subunits which are bonded together
Function is to store info
DNA base pairs
Adenine -> Thymine
Cytosine -> Guanine
Hydrogen bonded
DNA VS RNA
DNA = double helix (antiparallel strands of nucleotides linked by hydrogen bonding between complementary base pairs.)
DNA = Thymine
RNA= Uracil
DNA sugar = Deoxyribose
RNA = Ribose
DNA bonds
Covalent bonds attach the backbones of the nucleotides together
Skill: Draw simple diagram structure of singular nucleotide
Drawing DNA vs RNA
5’ carbon is at point of pentagon
Chromatin and supercoiling and nucleosomes
DNA wrapped around proteins called histones.
1 Nucleosome = a piece of DNA tightly wrapped around 8 Histone proteins
Watson and Crick
Evidence Watson and Crick used.
- X-Ray Crystallography
- Franklin’s Photo 51
- Models
Stahl Experiment
Rosalin Franklin
- Discovered the 2 backbones had to run in seperate directios
- Watson and Crick used tis to discoverthat the Sugars and Phosphates had to be on outside of helix
Erwin Chargaff
- Discovered that the # of A+T and C+G is the same
- Watson used this to discover the paired bases
Linus Pauling
- Pauling, Watson and Crick suspected DNA = Helix but didnt know arrangement
- Proposed tripple helix
- Crick used this to discover X-Ray diffusion of what helix pattern should look like
Watson and Crick
Suggested Semiconservitive replication
Hershey and Chase
used radioative 35S and 32P to infect bacteria
- 32P was inside bacteria & DNA due to P backbones
- 35S was not in bacteria as not in DNA
- Able to determine that DNA is genetic material not protein
