FINALS: CENTRAL DOGMA Flashcards
Biochemical process by which DNA molecules
produces exact duplicates of themselves.
DNA REPLICATION
DNA‘s code must be copied and taken to the
cytosol.
DNA TRANSCRIPTION
The process of copying the sequence of one DNA
strand, the TEMPLATE STRAND.
TRANSCRIPTION
the process of decoding the mRNA into a
polypeptide chain.
TRANSLATION
FACTS ON DNA REPLICATION
* DNA has to be ______ before a cell divides.
* DNA is copied during the __ or ______phase of
interphase.
* NEW CELLS will need ______ DNA strands.
copied; S, synthesis; identical
Cellular contents are duplicated
EXCEPT for the Chromosomes.
G1
Each of the 46 Chromosomes is
duplicated by the cell.
S
The cell “Double Checks” the
duplicated Chromosomes for error,
making any needed repairs.
G2
G1,S, G2
INTERPHASE
of hydrogen bonds of Adenine and Thymine
2
of hydrogen bonds of Guanine and Cytosine
3
3 replication models
conservative
semi-conservative
dispersive
- New strand is ½ parent template.
- ½ new DNA
SEMI-CONSERVAYIVE MODEL
breaks the hydrogen bonds of the parent DNA strands at the replication forks, which gives two separate DNA strands
Helicase
attach to the separated strands to keep them apart and the bases exposed
single-strand binding protein
synthesizes short RNA segments called primers that are starting points for DNA polymerase
Primase
catalyzes the formation of phosphodiester linkages on the new DNA strands between the 3’ ends of the growing chains and available complementary nucleotides
DNA Polymerase
DNA polymerase adds _________ continuously in the 5’ to 3’ direction to a growing DNA chain
nucleotides
At each primer, DNA polymerase form short, separate segments until it reaches the next primer and stops
Okazaki fragments
joins the okazaki framents
DNA ligase
DNA REPLICATION (1st step) Begins at a site called
ORIGIN OF REPLICATION
DNA REPLICATION (1st step) New strands grow at the
replication forks
DNA REPLICATION (1st step)
As the two strands open at the origin, ______________ ______________ form.
REPLICATION
BUBBLES
single bubble
PROKARYOTES (bacteria) –
many
bubbles.
EUKARYOTIC CHROMOSOMES
Attach and keep 2 DNA strands separated
and untwisted.
SINGLE-STRAND BINDING PROTEINS
Attaches to the 2 forks of the bubble to
relieve stress on the DNA molecule as it
separates
TOPOISOMERASE
the enzyme that synthesizes the RNA
PRIMER.
PRIMASE
A ________ is created to start the new strand.
“PRIMER”
DNA REPLICATION (2nd step)
Build daughter DNA strand.
Can operate on forming DNA
daughter strand only in the 5-to-3
direction.
DNA polymerase III
DNA polymerase can only add nucleotides
to the __ end of the DNA.
3’
Exonuclease activity removes RNA
primer and replaces with newly
synthesized DNA.
DNA pol I
Repair function
DNA pol II
Main enzyme that adds nucleotides
in the 5’-3’ direction.
DNA pol III