In the past, the prevailing opinion was that the genetic material was proteins and not DNA. What was the basis of this thinking?
Proteins more variety and higher level of structure.
100
Adenine makes up 28% of the nucleotides in a sample of DNA from an organism. Approximately what percentage of the nucleotides in this sample will be guanine?
22%
100
Enzymes that untwist the double helix at the replication forks.
Helicase
100
Explain the lagging strand.
It is the strand that is 5' to 3' against the replication fork.
100
The lagging strand is synthesized as a series of segments called ______ fragments
Okazaki
200
What investigators was/were responsible for the following discovery? Phage with labeled proteins or DNA was allowed to infect bacteria. It was shown that the DNA, but not the protein, entered the bacterial cells, and was therefore concluded to be the genetic material.
Hershey and Chase
200
What kind of chemical bond is found between paired bases of the DNA double helix?
Hydrogen
200
Binds to and stabilizes single-stranded DNA so it does not H-bond to itself.
Single Stranded Binding Proteins
200
What is the difference between dATP and ATP?
dATP is deoxyadenosine triphosphate (lacks an -OH group on the 2' carbon).
ATP is adenosine triphosphate
200
Viruses that infect bacteria
Phages
300
What scientist used X-ray crystallography to study molecular structure of DNA that Watson and Crick ultimately used to find the 3D structure of DNA?
Rosalind Franklin
300
Describe the "Back Bone" of a DNA double helix.
Sugar Phosphate Backbone
300
Starts an RNA chain from scratch and adds RNA nucleotides one at a time using the parental DNA as a template.
Primase
300
Catalyzes the elongation of new DNA at a replication fork.
DNA polymerase III
300
DNA winds around histones to form _________ “beads”
Nucleosome
400
Experiments by these scientists supported the semiconservative model.
Meselson and Stahl
400
What is the 5' and the 3' end of a nucleotide?
5' is the 5th carbon attached to the phosphate group.
3' is the 3rd carbon in the sugar base which is attached to a hydroxyl group.
400
What enzyme alleviate “overwinding” ahead of replication forks by breaking, swiveling, and rejoining DNA strands?
Topoisomerase
400
What enzyme fills in the gap between the 5' end the 3' end of two Okazaki fragments?
Ligase
400
Eukaryotic chromosomal DNA molecules have at their ends nucleotide sequences called __________.
Telomeres
500
This scientist found in any organism the amount of A = T, and the amount of G = C.
Chargaff
500
Interactions between nucleosomes cause the thin fiber to coil or fold into this thicker fiber
30nm Fiber
500
Replaces RNA with DNA.
DNA Polymerase I
500
A new DNA strand elongates only in the 5' to 3' direction because....
DNA polymerase can only add nucleotides to the free 3' end.
500
To repair a thymine dimer by nucleotide excision repair, what order do the necessary enzymes act?