2.3: nucleotides Flashcards
What is the monomer for nucleic acids
Nucleotide
What elements (letters not parts) are in a nucleotide
C H O N P
What bond forms between two nucleotides
Phosphodiester bond
What is the name of the polymer for nucleotides
polynucleotide
What is the structure of a DNA nucleotide?
- Phosphate group
- Pentose sugar (deoxyribose)
- Nitrogenous base A T C or G
What is the structure of a RNA nucleotide?
- Phosphate group
- Pentose sugar (ribose)
- Nitrogenous base A C G and U instead of T
What is ATP and ADP and describe its structure
Phosphorylated nucleotides.
ATP = 3 phosphate groups
ADP = 2 phosphate groups
Has ribose sugar and adenine base
Describe the structure of DNA
- DNA is a nucleic acid made of DNA nucleotides
- Has 2 polynucleotide chains connected by Hydrogen bonds
- Antiparallel chains
- Double helix shape
What’s the difference between a purine and a pyrimidine?
Purine has two carbon-nitrogen rings whereas pyrimidine has only one.
Purines are Adenine and Guanine
Pyrimidine are Cytosine Thymine and Uracil
How many hydrogen bonds between A and T
2
How many hydrogen bonds between C and G ?
3
How do the bases pair up
Complimentary base pairing between one pyrimidine and a purine
Describe DNA replication
- Semi conservative as one new and one old strand in each new helix
1. DNA helicase unzips the polynucleotide strand and breaks the H bonds to form 2 single strands
2. The original strands act as template and free floating nucleotides complementary base pair with the original polynucleotide to form a new strand
3. DNA polymerase forms H bonds between new nucleotides on new strand. Then H bonds reform and the polynucleotide strands recoil to form double helixes again - one new and one old strand
What are the features of the genetic code
- Universal
- Degenerate
- non-overlapping
What are the purines
Adenine Guanine
