DNA and RNA (Chapter 10) Flashcards
Genetic Material Must:
- Contain, in a stable form, the information about an organism’s cell structure, function, development, and reproduction
- Be able to be expressed
- expressed: how we use the information - Replicate accurately so that the progeny cells have the same information as the parent cells.
- Be capable of change
- without change, organisms are incapable of variation and adaptation.
Deoxyribonucleic Acid
DNA
Ribonucleic Acid
RNA
Have double stranded DNA as the genetic material
All known prokaryotes, eukaryotes, and a few viruses
Any molecule that serves as the genetic material must have the following characteristics except:
a. the ability to be replicated
b. the ability to store information
c. the ability to directly influence the development of traits
d. the ability to express information
e. the potential to be changed via mutation
c. the ability to directly influence the development of traits
- X-ray diffraction
- Chargaff’s Rule
- Known: polymer of nucleotides
- Knowledge of chemistry
Watson and Crick’s basis of designing a molecular structure of DNA
Nitrogenous Base + 5 Carbon Sugar
RNA
Nucleoside
Nitrogenous Base + 5 Carbon sugar + phosphate group
DNA
Nucleotide
Bond between nitrogenous base and 5 carbon sugar
glycosidic bond
where on the nucleoside indicates it will be part of RNA?
the OH/carbon 2’
Has two OH groups on 5 Carbon sugar
RNA
Has only one OH on 5 carbon sugar
DNA
Cytosine, Uracil, and Thymine
Pyrimidine Ring (smaller)
Adenine, Guanine
Purine Ring (larger)
Adenine, Guanine, Cytosine, Uracil, and Thymine
Nitrogenous bases
States that there is a 1:1 Ratio of A:T and G:C
A=T
G=-(triple bond)C
Chargaff’s Rule
Concluded that DNA is helical and that there are distinct regularities.
Franklin and Wilkins
360 degree turn = 3.4 nm/ 34 angstroms
Between bases = .34nm/ 3.4 angstroms
total gives 10bps/turn
Periodicites
5’–> 3’: forwards
3’–> 5’: backwards
3’ to 5’ phosphodiester bonds form the backbone
The Model
- Formed because of the angle of the glycosidic bond
- Right handed double helix
Model of B-DNA
Turns in right-handed direction no matter which end is being examined.
Right-Handed DNA
Major groove vs. Minor groove
Proteins can recognize the shape of the bases/the bonding potentials
-proteins recognize the major groove rather than the minor groove because of its size.
Both wind along the length of the molecule in an alternating pattern
In a polynucleotide, the individual nucleotides are linked by bonds between:
a. nitrogenous bases
b. sugar and phosphate
c. sugars
d. phosphates
e. nitrogenous base and sugar
b. sugar and phosphate
Which of the following is not included in the Watson-Crick model of DNA structure?
a. It is composed of two strands
b. The two strands are held together by H bonds between nitrogenous bases.
c. The strands run parallel.
d. The resultant helix is right-handed
c. The strands run parallel.
