CH3 nucleic acids Flashcards
1
Q
What are the two types of nucleic acid
A
DNA and RNA
2
Q
What is the structure of a nucleotide
A
- a pentose monosaccharide, either ribose or deoxyribose
- a phosphate group (PO4,2-)
- a nitrogenous base
3
Q
How are nucleotides linked together
A
- condesation reactions
- phosphate group at 5th carbon of pentose sugar forms covalent bond with hydroxyl group at third carbon
- bonds are phosphodiester bonds
- can be broken down by hydrolysis
4
Q
How does deoxyribose differ from ribose
A
One fewer oxygen atom
5
Q
What are the four bases of dna
A
- pyrimidine, one carbon ring, cytosine and thymine
- purine, two carbon ring, guanine and adenine
6
Q
What is the structure of DNA
A
- consists of two polynucleotide strands coiled into a helix
- two strands are anti-parallel
7
Q
What are the dna base pairing rules
A
- cytosine to guanine, forming three hydrogen bonds
- thymine to adenine, forming two hydrogen bonds
- pyrimidine always to purine so strands are always a constant distance apart
8
Q
What is the function of RNA
A
- plays role in transfer of genetic information from DNA to proteins
9
Q
How does RNA differ from DNA
A
- shorter
- single strand
- thymine replaced by uracil
10
Q
What are the different stages of DNA extraction
A
- grind sample in pestle and mortar, breaks down cell walls
- mix sample with detergent, breaks down cell membrane
- add salt, breaks hydrogen bonds of DNA and water
- add protease, breaks down proteins associated with DNA in nuclei
- add layer of alcohol, causes DNA to precipitate out of solution
11
Q
A
