DNA Replication — Steps & Enzymes
This enzyme unwinds the DNA double helix at the replication fork.
helicase
The strand synthesized continuously toward the replication fork.
leading strand
Two DNA strands are bound together via this type of bond.
Hydrogen bond
These scientists demonstrated that DNA was the genetic material using Strep pneumonia bacteria, proteases, and nucleases.
Avery, McLeod, and McCarthy
The ends of linear chromosomes are called ________, and the special enzyme used to ensure we don't lose them is ___________.
telomeres; telomerase
This enzyme synthesizes short RNA primers needed to start DNA replication.
primase
The strand synthesized discontinuously away from the fork.
lagging strand
These nitrogenous bases are purines and what are their complementary pairs?
Adenine and Guanine
A-T and G-C
This experiment proved that DNA, not protein, is the genetic material using bacteriophages.
the Hershey–Chase experiment
Eukaryotic chromosomes are what shape and have how many orgins of replication.
linear, multiple
The main enzyme responsible for adding nucleotides to the growing DNA strand in the 5′→3′ direction.
DNA polymerase III
Short DNA fragments produced on the lagging strand.
Okazaki fragments
The bond that links nucleotides along one DNA strand in the backbone.
a phosphodiester bond
This scientist used X-ray diffraction to reveal DNA’s helical structure.
Rosalind Franklin
Prokaryotes usually have this number of origins of replication per chromosome.
one
This enzyme removes RNA primers and replaces them with DNA nucleotides in prokaryotes.
DNA polymerase I
The reason the lagging strand is synthesized discontinuously relates to DNA polymerase III only creating the new strand in which direction.
5′ to 3′
Which scientist discovered the complementary base pairs (A-T and G-C)?
Chargoff
These two scientists proposed the double helix model of DNA in 1953.
James Watson and Francis Crick
Describe the function of telomerase
Replaces the RNA primer with DNA at the 3' end
This enzyme seals nicks in the sugar-phosphate backbone by forming phosphodiester bonds.
DNA ligase
This structure forms where the double helix is opened and both strands are copied.
replication fork
Describe the semiconservative model of DNA replication
new DNA is made up of one parental strand and one new strand
This conclusion from Griffith’s work described the transfer of genetic information between bacteria.
transformation
Describe telomerase activity as we age and in cancer cells.
decreases as we age; increased in cancer cells