nucleotides and phosphodiester bonds Flashcards
what are nucleotides?
many repeating units (monomers) in the nucleic acids
what three things are nucleotides formed from?
- a pentose sugar
- a nitrogenous base
- a phosphate group
give the three components of a DNA nucleotide:
- a deoxyribose sugar with the hydrogen group at position 2’
- one of four nitrogenous bases
- a phosphate group
give the three components of an RNA nucleotide:
- a ribose sugar with an OH group at position 2’
- one of four nitrogenous bases
- a phosphate group
give the four nitrogenous bases in DNA:
- Adenine (A)
- Thymine (T)
- Cytosine (C)
- Guanine (G)
give the four nitrogenous bases in RNA:
- Adenine (A)
- Uracil (U)
- Cytosine (C)
- Guanine (G)
what does the presence of the hydroxyl group do for RNA?
makes RNA more susceptible to hydrolysis, hence why it is used as the transport molecule, rather than the storage molecule (DNA)
what are pyrimidines?
nitrogenous bases that have a single ring structure
what are purines?
nitrogenous bases that have a double ring structure
what three bases are pyrimidines?
- Cytosine
- Thymine
- Uracil
what two bases are purines?
- Adenine
- Guanine
Is DNA or RNA single stranded?
RNA
how is a phosphodiester bond formed?
through the condensation reaction between two nucleotides
what is a polynucleotide?
substances made up of many nucleotides joined together in long chains
where does the condensation reaction occur?
between the phosphate group of one nucleotide and the pentose sugar of the next molecule
