2.6 Structure of DNA and RNA Flashcards
what are nucelic acids and nucleotides (structure)?
nucleic acids aka RNA and DNA are polymers or polynucleotides made up of repeating units of the monomer nucleotides
DNA has two antiparralel strands in helix shape. One strand is oriented in the direction 5’ to 3’ and the other the other way around
nucleotides have three parts
- sugar which is a pentose sugar either ribose or deoxyribose
- phosphate group which is charged negativelt and is acidic
- base that contains nitrogen and has either 1 or 2 rings if its a pyrimidine (CUT, 1 ring) or a purine (2 rings, AG)
the base and the phosphate are linked to the sugar with covalent bonds, the one between the phosphate and the suagr is called a phosphodiester bond and is attached to carbon 3 and 5 or the sugar
between teh bases the bonding is 2 hydrogen bonds betwen A and T and 3 hydrogen bonds between C and G
the sugar phosphate backbone ensures that the information of the base sequence and the genetic code is stable and secure
Rna vs DNA
- Dna has deoxyribose (1 fewer oxygen) rna has ribose
- dna is double stranded RNA is single stranded
- RNA has uracil instead of thymine in DNA
how is the nucleotide formed?
a condensation reaction occurs releasing water
how does ATP work and how is it connected to nucleotides
also what is a nucleoside vs nucleotide
a nuleotide with more than one phosphate group is called a phosphylated nucleotide
when we break off a phosphate we provide energy for metabolic pathways
the nucleoside is just the sugar and the base while the nucleotide includes at least one phosphate group
what are purines and pyrimidines
purines are A or g and they have a double ring while pyrimidines are CUT
purines always bond to pyrimidines and the hydrogen bonds between them always have the same lengths for stability
