Chapter 14 Flashcards
Pyrimidines
Cytosine, thymine
Uracil (RNA)
Purine
Adenine Guanine
Nucleotides
Cytosine, thymine, adenine, guanine, uracil
5’end (phosphate group)
Thymine, cytosine
3’end (hydroxyl)
Adenine
Guanine
Base pair stabilize by hydrogen bonds
Adenine - thymine
Guanine - cytosine
A new DNA strand can elongate _______ in the ____________ direction
Only,
5’ to 3’
Topoisomerase
Under winding or over winding of DNA
DNA Helicase; opens up the DNA helix by _________________
Breaking the hydrogen bonds
Primase
Synthasize the RNA primer
Primer is needed for DNA pol to start _________ of new DNA strand
Synthesis
(DNA Polymerase)
Removes RNA primer with new DNA
DNA pol 1
DNA Pol 2
Repairs
(DNA polymerase)
Adds nucleotides in the 5’3 direction
DNA pol 3
Linkage between 5’ OH and 5’ phosphate ends of DNA, seals Okazaki fragments
DNA ligase
Special nucleotide sequence end of DNA in eukaryote
Telomeres
Catalyze lengthening of telomere
TeloMERASE
How repairs are made to DNA
Proofreading
Mismatched bases are removed after replication
Mismatch repair
Enzyme replace incorrect bases by making a cut 3’ and 5’ ends
Nucleotide excision repair
Mutation affect a single base Pair
Point mutation
Purine or pyramidine being replaced by base of same kind
Transition substitution
Insertion or deletion of nucleotide may result in a shift in the reading frame or insertion of a stop condone
Frameshift mutation
