Module 5: RNA and DNA structure and function Flashcards
RNA nucleotide is comprised of
Phosphate group, pentose sugar, and a nitrogenous base
The directionality of the phosphate group end of a DNA strand is
5’
The directionality of the pentose sugar end of a DNA strand is
3’
RNA is autocatalytic, meaning
It can form structures with itself
True or false: RNA is single stranded
TRUE
Purine bases have ____ carbon rings
Two
Pyrimidine bases have _____ carbon ring
One
Coding strand (strand that isn’t being translated) runs in the
5’ to 3’ direction
The template strand (strand being transcribed) runs in the
3’ to 5’ direction
DNA is translated in the ____ to ____ direction
5’ to 3’ direction
Typical tRNA direction is
3’ to 5’
______ strand has Okazaki fragments
Lagging
Growth of new DNA strands (polymerization) is catalyzed by DNA _____
polymerase
Addition of nucleotides requires energy; incoming nucleotide trisphosphates serves as both the source of new nucleotides and ____
energy
DNA degeneracy
refers to the fact that multiple codons, or sets of three nucleotides, can code for the same amino acid during protein synthesis.
Removes RNA primer and replaces it with newly synthesized DNA
Polymerase I
Main enzyme that adds nucleotides in the 5’ to 3’ direction
Polymerase III
Opens the DNA helix by breaking hydrogen bonds between the nitrogenous bases
Helicase
Seals the gap between the Okazaki fragments
Ligase
Synthesizes RNA primers needed to start replication
Primase
Helps to hold the DNA polymerase in place when nucleotides are being added
Primase
Helps relieve the strain on DNA when unwinding
Topoisomerase
Binds to single-stranded DNA to prevent DNA from rewinding back
Single-strand binding proteins
p_______ is one importance function of DNA polymerase
Proofreading
