Structure of DNA (Chapter 14) Flashcards
Scientific name of green algae
Acetabularia
The hammerling experiment discovered _____.
hereditary information is stored in the cell’s nucleus
Hammerling’s reciprocal graft experiment discovered _____.
the nucleus in the base of the mushroom determines the type of cap regenerated
The griffith experiment documented _____.
movement of genes from one organism to another (transformation).
The griffith experiment discovered _____.
movement of material can alter the genetic makeup of the recipient cell
Griffith’s discovery of transformation used _____ and mice.
S. pneuomoniae
The avery experiment discovered _____ and _____.
removal of almost all lipid and protein from bacteria didn’t reduce transforming activity
DNase destroys all transforming activity
The hershey-chase experiment discovered _____ by _____.
hereditary information was DNA, not protein
labeling DNA and protein with radioactive isotope tracer
_____ is the transforming agent allowing rough bacteria to make a smooth coat an allow infection.
DNA
A virus has a _____ “head” and a _____ core.
protein
DNA
Infection occus when a virus injects _____ into _____.
DNA
a bacterial cell
Bacteriophage
Virus that infects bacteria
DNA is a ____.
nucleic acid
DNA is composed of _____.
nucleotides
Deoxyribose is a _____.
five-carbon sugar
The nitrogenous base of DNA can be _____ (A), _____ (T), _____ (C), and _____ (G).
adenine
thymine
cytosine
guanine
DNA is composed of a _____, _____, _____, and a _____.
5-carbon sugar
phosphate group
nitrogenous base
free hydroxyl group
Purine nitrogenous bases of DNA and RNA are _____ (A) and _____ (G).
adenine
guanine
Pyrimidine nitrogenous bases are _____ (C), _____ (T), and _____ (U).
Cytosine (DNA+RNA)
Thymine (DNA)
Uracil (RNA)
The chain of nucleotides has a ‘-to-’ orientation.
5
3
The bond formed between adjacent nucleotides is a ______ bond.
phosphodiester
Erwin Chargaff determined that _____, _____, and _____.
Chargaff’s Rules
amount of adenine = thymine
amount of cytosine = guanine
proportion of purines and pyrimidines are equal
Rosalind Franklin performed X-ray diffraction studies to discover _____.
the 3D helical structure of DNA
DNA has a diameter of _ nm and makes a complete turn of the helix every _ nm.
2
3.4
_____ and _____ deduced the structure of DNA.
James Watson
Francis Crick
_____ (A) forms _____ bonds with _____(T).
Adenine
2 hyrdrogen
thymine
_____ (G) forms _____ bonds with _____ (C).
Guanine
3 hydrogen
cytosine
Hydrogen bonds between DNA bases break to allow _____.
strand separation
Each DNA strand is a _____ for the synthesis of a new strand.
template
Template strands determine the sequence of bases in the _____.
daughter strand
complementary base pairing rules
Conservative (____)
organization of DNA strands
rejected
old/old + new/new
Semiconservative (_____)
organization of DNA strands
supported
old/new + old/new
Dispersive (_____)
organization of DNA strands
rejected
mixed old and new on each strand
To test the potential mechanisms for organization of DNA strands, E. coli grew in media with _____ and then in media with _____.
heavy nitrogen
lighter nitrogen
Replication of DNA is _____.
semiconservative
The junction of the unwound molecules of DNA is a _____.
replication fork
A new strand is formed by pairing complementary bases with the _____.
old strand
DNA replication produces _ molecules of DNA.
2
DNA replication produces strands, each containing one _____ and _____ strand.
old
new
_____ are the mechanism for DNA replication.
Enzymes
The building blocks to make a copy of DNA are _____.
nucleotide triphosphates
DNA replication consists of three stages:
Initiation
Elongation
Termination
Initiation always occurs at _____.
the same site
The majority of replication is spent in the _____ phase.
elongation
_____ cannot link the first nucleotides in a newly synthesized strand of DNA.
DNA polymerase
_____ constructs an RNA primer.
RNA polymerase
DNA polymerase adds nucleotides to the _’ end of DNA.
3
The leading strand replicates _____ the replication fork.
toward
The lagging strand elongates _____ the replication fork.
from the
One strand of the newly made DNA is synthesized continuously. This is the _____ strand.
leading
The _____ strand is made in small precursor fragments, known as _____ .
lagging strand
Okazaki fragments
Okazaki fragments are _____ base pairs in length.
100-200
DNA polymerase matches existing DNA bases with _____ and links them.
complementary nucleotides
DNA polymerase synthesizes in a ‘-to-’ direction.
5
3
DNA polymerase requires _____.
a primer of RNA
Replicon
DNA controlled by an origin
E. coli has _ DNA polymerases.
3
DNA polymerase I
pol I
Acts on lagging strand to remove primers and replace them with DNA.
DNA polymerase II
pol II
Involved in DNA repair processes
DNA polymerase III
pol III
Main replication enzyme
Prokaryotic DNA polymerases have ‘-to-’ exonuclease activity.
(proofreading)
3
5
DNA polymerase I (pol I) has ‘-to-’ exonuclease activity.
5
3
Unwinding DNA causes _____.
torsional strain
Helicases
use energy from ATP to unwind DNA
Single-strand-binding proteins (SSBs) coat strands to _____.
keep them apart
_____ prevents supercoiling.
Topoisomerase
_____ is used in prokaryotic DNA replication to prevent supercoiling.
DNA gyrase
Eukaryotes usually have _____ origins of replication.
multiple
DNA polymerase can synthesize in _ direction(s).
1
The leading strand is synthesized continuously from _____.
an initial primer
The lagging strand is synthesized _____ with multiple _____.
discontinuously
priming events
A _____ forms a “sliding clamp” to keep it attached to the leading strand.
beta-subunit
