4.3 Flashcards
DNA helicase (function)
unzips DNA helix
DNA polymerase (function)
moves along separated strands and produces complementary strands
DNA ligase (function)
fills in the gaps between Okazaki fragments on lagging strand
1 parental DNA molecule makes ___ new daughter DNA molecules
this process is called ___
2
semiconservative replication
DNA helicase…
opens the DNA helix, exposing the nitrogenous bases
DNA polymerase…
reads nitrogenous bases and matches them w/ complementary free nucleotides
DNA ligase…
joins the newly synthesized segments of DNA
which molecule usually detects and corrects errors in DNA replication?
DNA polymerase
exposure to chemicals and radiation may lead to changes in DNA structure called ___
mutations
G1 phase (def)
interval b/n cell division and DNA replication
cell synthesizes proteins, grows, and carries out is preordained tasks for the body
cell accumulates the materials needed to replicate its DNA in the next phase
how accurate is DNA replication?
the few errors made by DNA polymerase are usually corrected by DNA polymerase or other repair enzymes
describe events that occur during the synthesis (S) phase of the cell cycle
a cell makes a duplicate copy of its centrioles and all of its nuclear DNA
what occurs during the G2 phase of the cell cycle?
cell synthesizes enzymes that control cell division and also checks and repairs the newly copied DNA
during the cell cycle, G1, S, and G2 collectively make up the phase known as what?
interphase
S phase (def)
period of synthesis during which a cell makes a duplicate copy of its centrioles and all of its nuclear DNA