Genomes Flashcards
Cell expands _______ at the same time that it replicates DNA
Cytoplasm
The ______ grows from each side of the cell, separating the 2 ______ ______
The septum grows from each side, separating the 2 daughter cells
What does a replication bubble consists of and what do they do?
A replication bubble consists of 2 replication forks that move in two different directions around the chromosome
To replicate DNA the double helix must _______. Exposing bases (__,__,__,__) that can pair with another base on the growing (____) strand.
The double helix must unwind. Exposing bases A, T, G, C. That can pair with anotherbase on the growing (new) strand.
What does Helicase do?
Helicase breaks the hydrogen bonds between nitrogenous bases, opening the DNA helix
What does single stranded binding proteins do? (SSBP)
Bind to the newly exposed single stranded DNA and blocks formation of hydrogen bonds and nitrogenous bases
What is the purpose of topoisomerase II (DNA gyrase)?
Relieves the supercoiling of the chromosome by breaking and resealing the DNA
New DNA is synthesized by ___ ______ __ using old DNA as a template. New DNA is synthesized in what direction? (2 part question)
DNA polymerase Ill
5’—> 3’
DNA polymerase Ill cannot synthesize ____ __ ___
DNA de novo
What is every new strand Of DNA initiated with?
RNA primer
____ builds the short RNA primer
Primase
What helps hold DNA polymerase Ill onto chromosome during replication?
A protein sliding clamp
What end does DNA strands elongate at?
3’ end
The leading strand is synthesized….
Continuously
The lagging strand is synthesized…..
Discontinously in Okazaki fragments
To connect the small Okazaki fragments of the lagging strand into one continuous strand of DNA
DNA polymerase I does what?
DNA ligase does what?
DNA polymerase 1 removes RNA primer and fills the resulting gap with DNA (exonuclease activity)
DNA ligase seals the gaps between adjacent fragments of DNA