Nucleotides and Nucleic Acids Flashcards
1
Q
How many H bonds form between the complementary bases in DNA?
A
Adenine and Thymine - 2 H bonds
Cytosine and Guanine - 3 H bonds
2
Q
Explain how to extract DNA from plant material
A
- Grind sample with pestle and mortar to break the cell walls down
- Mix sample with detergent to disrupt phospholipid bilayer and break down the cell surface membrane, releasing cell contents into solution
- Add salt to break the H bonds between the DNA and water molecules
- Add a protease enzyme to break down the proteins associated with the DNA in the nuclei
- Add a layer of ethanol on top of the sample to cause the DNA to precipitate out of the solution
-DNA can be seen as white strands
3
Q
What is meant by the genetic code being universal?
A
Each DNA triplet codes for the same amino acid in all organisms (bar a far exceptions)
4
Q
Describe the difference between a purine and a pyrimidine
A
- Purines are larger and have 2C ring structures (AG)
- Pyrimidines are smaller and have 1C ring structures (TC)