Flashcards
FLASHCARDS: 7.1 - DNA Structure & Replication
Flashcards do conjunto (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
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- O usuário eliminou as informações de disciplina FlashCards sobre FLASHCARDS: 7.1 - DNA Structure & Replication, criado por Usuário eliminado em 20-02-2020.
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- Usuário eliminado · fev 2020
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- Criado por Blen Abate · 18 fev 2020
- Copiado por Blen Abate · 20 fev 2020
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