Chapter 16 Flashcards
Who of credited with explaining the structure of the DNA double helix?
Watson and Crick
What is required for DNA replication?
RNA primer
Proteins that are involved in packaging the eukaryotic chromosome into “beads” called __ are __
Nucleosomes; histones
Histones
Proteins that are responsible for the first level of DNA packing in chromatin
Evidence to support that DNA strands run anti parallel to each other includes
Hydrogen bonding interactions
X-Ray measurement data
The nitrogenous bases are on the inside
Chargaff’s rules
The information in DNA is contained in
The sequence of nucleotides along the length of the two strands of the DNA molecule
The role of DNA polymerase in DNA replication is to
Attach free nucleotides to the new DNA strand
Telomeres are
Repeating noncoding sequences at the ends of linear eukaryotic chromosomes
A virus that infects bacteria is called a __, which is made up of the macromolecules __ and __
Bacteriophage
DNA
Protein
DNA polymerase are the enzymes that
Catalyze the addition of nucleotides to a preexisting chain
When __ form after an exposure to ultraviolet (UV) light, a __ can remove the damaged nucleotides and replace them with normal nucleotides
Thymidine dimers
Nucleotide excision repair enzyme
A segment of the strand containing damage is
Cut out (excised) by a DNA-cutting enzyme — a nuclease — and the resulting gap is filled in with nucleotides, using the undamaged strand as a template
Enzymes involved in filling the gap are
DNA polymerase
DNA kinase
Nucleotide excision repair enzyme
DNA repair system
Enzyme
Griffith showed that dead __ cells transform living __ cells into living __ cells
Pathogenic
Nonpathogenic
Pathogenic
The 5’ end of a DNA strand always has a free __ group while the 3’ end always has a free __ group
Phosphate
Hydroxyl
Griffith showed that dead __ cells transform living nonpathogenic cells into __ cells
Pathogenic
Nonpathogenic
DNA replication begins at a site called the origin of replication, forming a bubble, which is followed by a __, where parental strands are unwound by __
Replication forks
Helicases
Replication of a chromosome begins at a site called
Origin of replication
Origins of replication
Short stretches of DNA having a specific sequence of nucleotides
Why were so many of the early experiments on DNA carried out on viruses and bacteria?
They have relatively small genomes
Their chromosomes have a simpler structure
They have short generation times
They can interact with each other
The unwinding of DNA at the replication fork causes twisting and strain in the DNA ahead of the fork, which is revealed by an enzyme called
Topoisomerase
Replication of the lagging strand of DNA is accomplished by repeatedly making __ followed by 1,000-2,000 nucleotide segments called
Short RNA primers
Okazaki fragments
DNA polymerase adds nucleotides to the __ of the leading strands, and to the __ of the lagging strands (Okazaki fragments)
3’ end
3’ end
In DNA, the two purines are __ and the two pyrimidines are __
Adenine and guanine
Cytosine and thymine
The two sugar-phosphate strands that form the rungs of a DNA double helix are joined to each other through __
Hydrogen bonds between nucleotide bases
In DNA replication, the next nucleotide if incorporated into the growing polymer at the __ of the molecule by an enzyme called __
3’ (hydroxyl) end
DNA polymerase
DNA replication is correct
Helicases separate the two strands of the double helix, and DNA polymerase and then construct two new strands using each of the original strands as templates
Evidence to support that DNA strands run anti parallel to each other includes
Nitrogenous bases are on the inside
Chargaff’s rules
Hydrogen bonding interactions
X-ray measurement data
The role of DNA polymerase in DNA replication is to
Attach free nucleotides to the new DNA strand
DNA replication
DNA is copied
Transformation
Change in genotype and phenotype due to the assimilation of external DNA by a cell
Bacteriophages
Bacteria eaters