Chapter 19.1 Flashcards
What are the parts of interphase
G1 Phase, S phase, G2 Phase
what happens in G1 Phase
cell expansion
what happens in S phase
DNA synthesis
what happens in G2 phase
Structures for mitosis are created
What are the parts of M Phase
mitosis and cytokinesis
cytokinesis
division of cell
mitosis
division of nucleus
what must happen before you can make a new cell (regarding DNA)
must copy the DNA
what are the basic steps of DNA replication
H bonds are broken and each strand acts as a template to create a new complimentary strand
semi-conservation replication
each new DNA helix is now half old and half new DNA
Theta replication
one method of replication of circular DNA
steps of theta replication
begins at single origin, creates two replication forks and proceeds bi-directionally around the circle
replicons
multiple replication units
seen in eukaryotic DNA
Origin Recognition Complex (ORC)
binds to a replication origin
minichromosome maintenance complex (MCM Complex)
contains enzymes (DNA helicases) that can unzip DNA
what does it mean for DNA to be licensed
it is ready to be duplicated
what are the triophosphate deoxynucleoside derivatives
dATP, dTTP, dGTP, dCTP
the cleavage of the two terminal phosphates provides energy for polymerization
leading strand
continuous and in the 3’-5’ direction so DNA can be synthesized 5’-3’
lagging strand
5’-3’ so DNA has to be synthesized in okazaki fragments
Proteins involved in unwinding DNA
DNA helicases, topoisomerases, and SSB’s
DNA helicases
breaks the H bonds to unwind the DNA
topoisomerase
prevents DNA from supercoiling as it’s being unwound
Single-Strand DNA Binding Proteins (SSB)
binds to single-stranded DNA at replication fork and keeps DNA unwound
DNA replication enzymes in prokaryotes
DNA Polymerase I, II, III
exonuclease activity
proofreads
replisome
replicating enzyme complex that carries out DNA synthesis at replication fork
DNA polymerase III
reads 3’-5’ template to synthesize the new strand 5’-3’
continuous
primosome
primase and 6 proteins that unwind DNA, recognize the base sequence, and initiate replication. later the RNA is removed and replaced with DNA
what is the role of RNA primer, primase
to act as a starting point for synthesis of the new DNA
DNA Ligase
attaches to any breaks and joins okazaki fragments
DNA polymerase I
jumps in and changes RNA primer to DNA
basics of lagging strand synthesis
primase comes in and synthesizes a starting point for the DNA polymerase III. It will synthesize 5’-3’ and create an okazaki fragment. then DNA poly I comes and replaces the primer with DNA and finally DNA ligase attaches and joins the any breaks and fragments
which end are nucleotides degraded from
3’
mutation
any change in DNA sequence
DNA mismatch repair
the helix is distorted if bases don’t match up right which can be recognized and fixed
spontaneous mutations include:
depurination and deamination
depurination
loss of A or G
deamination
change of C to U
types of induced DNA damage
Radiation or chemicals
Thymine dimers
2 T’s covalently bond so they won’t H bond
intercalate
insertion of chemicals into DNA strands
basic steps for repair
endonuclease excises damaged DNA
DNA polymerase fills in the gap
Nick sealed by DNA ligase
