Nucleotides Flashcards
_____ and ___ cause the heat stands to separate but DO NOT break the phosphodiester bonds
Heat and Alkali
Name the purine and pyrimidine bases
Purine - Adenine, Guanine
Pyrimidine - Cytosince, Thymine
A-T, C-G
Histones contain large amounts of ____ amino acids.
Lysine and arginine
Eukaryotic mRNA contains a cap structure and poly A tail. The cap structure consists of ___ at the 5’ end
methylated guanine triphosphate
____ has a cloverleaf structure that contains modified nucleotides. Its relatively small containing 80 nucleotides.
tRNA
Modified nucleotides contain pseudouridine, dihydrouridine, ribothymidine
All tRNA molecules have a similar cloverleaf structure even though their base sequences differ. The first loop contains ___, the middle loop contains ____ which base-pairs with the codon in mRNA, the third loop contains____, and the CCA sequence at the 3’ end
First loop - D loop, dihydrouridine
Middle loop - anticodon
Third loop - TyC loop, ribothymidine and pseudouridine
DNA polymerase cannot initiate synthesis of a new strand. It copies in the ____ direction and synthesize new strand in the ____ direction
Copy: 3’ to 5’
Synthesizes new strand: 5’ to 3’
Its primer: a short stretch of RNA
____ unwind the helix, while ____ prevent extreme supercoiling
Helicases unwind
Topisomerases prevents supercoiling
Eukaryotic DNA polymerase used exclusively for repair
DNA polymerase beta
Eukaryotic DNA polymerase that acts as the lead polymerase on the lagging strand during replication
DNA polymerase delta
Eukaryotic DNA polymerase acts as the lean polymerase in the leading strand of the DNA
DNA polymerase epsilon
Eukaryotic DNA polymerase that functions exclusively in the mitochondria
DNA polymerase gamma
DNA _____ joins by forming phosphodiester bond, two adjacent DNA strands that are bound tot he same template
DNA ligase
Also joins Okazaki fragments
____ is a type of mutation where there is a substitution of one base for another
point mutation
____ is a type of mutation where one or more nucleotides are added within a DNA sequence
Insertions
_____ is a type of mutation where one or more nucleotides are removed within a DNA sequnce
deletions
_____ involves a specific glycosylase that removes a damaged base by hydrolyzing N-glycosidic bond, producing apurinic or apyrimidinic site
base excision repair
_____ involves a removal of a group of nucleotides from a DNA strand
nucleotide excision repair
____ is the removal of the portion of newly synthesized strand of a recently replicated DNA that contains a pair of mismatched bases
mismatch repair
_____ occurs when the transcrition apparatus (synthesizing RNA from DNA) detects DNA damage in the gene being transcribed.
transcription-coupled repair
Draw your purine base
Purine = 2 rings
Draw your pyrimidine base
Pyrimidine = 1 ring
Most nucleosides contain __
D-ribose or 2-deoxydy-D-ribose linked to N1 of pyrimidine or N9 of purine
Nucleosides attach to what nitrogen in purine
N9
