DNA Structure And Replication Flashcards
Hershey and chase proved DNA is the genetic material
They infected bacteria with a virus to see which molecule the virus injected into the bacteria
The 2 hypothesis of genetic inheritance
Protein and DNA
Chargaff rule?
A=T and C=G
Who produce the first pic of DNA using crystallography?
Rosalind Franklin
What is the backbone of the DNA made ?
Sugar, deoxyribose, and phosphate
What is the interior of a DNA molecule made ?
Nucleotide bases.
• Amine, thymine, Guanine, Cytosine
What antiparallel means ?
Strands go in opposite directions
What are the 4 nitrogenous bases?
Amine, Thymine, Cytosine, Guanine
How nitrogenous bases attach to another ?
Hydrogen bonding
What is a histone?
Protein that helps package in to coils
What’s template strand and daughter strands of DNA?
The temple strand is use as base to copy a new “ daughter” strand
Hypothesis of how DNA is replicated ?
- Conservative: DNA unwinds and replicates, and then which strand reattaches to the other strand
- semiconservative: DNA unwind and replicates, then each strand pairs with new daughter strand
- dispersive: each strand is composed by bits of template and daughter strand
What hypothesis was correct?
Semi-conservative. A heavy isotope of hydrogen was use to grow the bacteria, which incorporated into the DNA. After the notice the DNA was between heavy and normal.
Origen of replication
Where the DNA begins to unwind
What direction replication proceeds?
Both 5 to 3 and 3 to 5
Which organism has more origins of replications.?
Eukaryotes
What’s replication fork?
Where two strand of DNA are separated and unwound
What is the enzyme that unzips the DNA
Helicase
What single strand binding protein do
Help keep the separated strand of DNA from reattaching.
What are dATP, dGTP, dCTP, and dTTP?
Molecules with one nitrogenous base and 3 phosphate. They have a lot of energy and can be incorporated into growing DNA strand
Why RNA primers necessary for replication ?
Because DNA polymerase cannot bind by itself to DNA
Which end nucleotide bases get added ?
3’
What direction does the DNA strand grow?
5’ to 3’
Difference between the new daughter strands ?
One strand grows 5 to 3 the other one has to add DNA backwards ( Okazaki fragments)
