Week 10 (DNA structure, organization and replication) Flashcards
DNA is a type of _______ with each nucleotide being composed _____
nucleic acid
-5 carbón sugar
-phosphate group
-nitrogenous base
phosphodiester bond
when nucleotides are assembled together they are put in place with these covalent bonds
pyrimidines
small bases
C,T,U
purines
large bases
-adenine, guanine
griffith experiment
suggested that bacteria can transfer genetic info thru a process called transformation
hershey chase experiment
confirm that DNA is a genetic material
watson and crick
said that DNA is an intertwined double helix
Chargaffs rule
A-T
C-G
they form weak hydrogen bonds between the bases
DNA is what kind of configuration
antiparallel
conservative model vs dispersive model vs semi conservative model
conservative - two dif double helix’s
dispersive - chunks of each in each strand
semi conservative - one of each in a helix
what strand begins and what strand is synthesized
-template strand begins
-complementary strand is synthesized
how many sites of origin for euk vs pro
pro- single site
euk - multiple sites of origin
what is DNA pol III and what does it do and what does it require
it’s an enzyme
-adds nucleotides to the pre existing growing complementary strand 3’ end
-requires an RNA primer
sliding DNA clamp
protein that encircles DNA and attaches DNA pol III to template strand - increasing rate of DNA synthesis
leading strand
-replicates towards replication fork
-synthesized continuously
lagging strand
replicates away from replication fork
-synthesized in fragments
okazaki fragments
DNA replication is referred to as….
semi discontinuous
helicase
unwinding of duplex
topoisomerase
removes torsional strain
primase
builds a primer
DNA pol III vs DNA pol I
pol III - assembles complementary strands
pol I- removes primer
DNA ligase
joins fragments on lagging strand
order of events of replication on lagging strand
1-replication proteins
2-helicase
3-SSBPs (hold strands apart )
4-primase
5-DNA pol III
6–DNA pol I
7-ligase
what proofreads strands
DNA pol III
telomeres and where is it added
-prevent chromosomes from shrinking during replication
-telomerase adds to 3’ end
nucleoside
5 carbon sugar and nitrogenous base
NO PHOSPHATE GROUP
nuclease
capable of breaking the phosphodiester bonds
