Flashcards
FLASHCARDS: 7.1 - DNA Structure & Replication
Cards in this deck (16)
- 1What are histones used for?they are used by the cell to package DNA into nucleosomes
- 2Nucleosomeconsists of a central core of 8 histone proteins with DNA coiled around them
- 3What is supercoiling good for?it allows a great length of DNA to be packed into a small space in the nucleus
- 4How does replication happen on the leading strand?the strand is made continuously following the fork as it opens
- 5How does replication happen on the lagging strand?the strand is made in fragments moving away from the fork
- 6Direction of replication5' to 3'
- 7coding sequencesthe DNA sequences that code for the production of polypeptides
- 8Helicaseunwinds and separates the double-stranded DNA by breaking the hydrogen bonds b/n base pairs, this happens at the origins of replication, creating a replication fork of two strands running in antiparallel directions
- 9DNA gyrasereduces the torsional stain created by the unwinding of DNA by helicase through negative supercoiling
- 10Topoisomerasereleases the strain that develops ahead of the helicase
- 11single-stranded binding proteinsbind to the DNA strands after they've been separated and prevent the strands from re-annealing, they also help prevent the single-stranded DNA from being digested by nucleases, they will be dislodged from the strand when a new strand is synthesized
- 12DNA primasegenerates a short RNA primer (~ 10-15 nucleotides) on each of the template strands, it provides an initiation point for DNA polymerase III, which can extend a nucleotide chain but not start one
- 13DNA polymerasecovalently links the deoxyribonucleotide monophosphate to the 3' end of the growing strand
- 14DNA polymerase IIIattaches to the 3' end of the primer and covalently joins the free nucleotides together in a 5' to 3' direction, it moves in opposite directions on the two strands
- 15DNA polymerase Iremoves the RNA primers from the lagging strand and replaces them with DNA nucleotides
- 16DNA ligasejoins the Okazaki fragments together to form a continuous strand, it does this by covalently joining the sugar-phosphate backbones together with a phosphodiester bond
Information
- Description
- User has deleted their subject information Flashcards on FLASHCARDS: 7.1 - DNA Structure & Replication, created by Deleted user on 20/02/2020.
- Created by
- Deleted user · Feb 2020
- Updated
- Feb 20, 2020
- Views
- 13
- History
-
- Created by Blen Abate · Feb 18, 2020
- Copied by Blen Abate · Feb 20, 2020
- Rating