CH 14.2: DNA Structure Flashcards
1
Q
What are the 3 characteristics of DNA?
A
- 5 carbon sugar
- Phosphate (PO4-) group
- Nitrogenous base
2
Q
What are the bases that pair with eachother?
A
- A and T= 2 hydrogen bonds
- C and G= 3 hydrogen bonds
3
Q
What class does the nitrogenous bases C,T,U pertain to?
A
-Pyrimidines
4
Q
What class does the nitrogenous bases A and G pertain to?
A
-Purines
5
Q
Where is Thymine present?
A
-In DNA ONLY
6
Q
Where is Uracil present?
A
-In RNA ONLY
7
Q
What is a Phosphodiester bond?
A
-It links the 2 sugars in the backbone of the nucleic acid molecule via ester bonds
8
Q
What do DNA and RNA almost always have on their ends?
A
-A free 5’ phosphate group at one end & a free 3’ hydroxyl group in the other
9
Q
What are the 2 underlying ratios of DNA?
A
- The amount of Adenine in DNA always equals the amount of Thymine
- The amount of Guanine in DNA always equals the amount of Cytosine
10
Q
What are Charriff’s rules?
A
- The proportions of A=T and G=C
- The ratio of C-G and A-T varies w/ different species
11
Q
How to the Nucleotides attach to eachother?
A
-Via hydrogen bonds
