Chapter 28 Flashcards
Which of the following events can result from damage to DNA that is NOT appropriately repaired?
cell death
alteration to DNA sequence that can be inherited by progeny
stalling of DNA replication
cell transformation and cancer
Which of the following repair mechanisms could be used for a DNA double-stranded break?
nonhomologous end joining
Why is an RNA molecule required during DNA replication?
to initiate strand synthesis
Which of the following repair mechanisms uses an enzyme such as UvrABC to cut out an oligonucleotide containing the damaged DNA?
nucleotide-excision repair
During the replication of prokaryotic DNA,
one strand is synthesized continuously and the other is synthesized in short segments.
In the Ames test, _____ is used as the control while _____ is used to make certain that the system is working
water; a known mutagen
The major way in which DNA interacts with specific proteins is through
hydrogen bonding to bases through the major and minor grooves in the DNA double helix
If a DNA molecule is damaged, it
is possible to repair the damage in the site where it occurs.
The primase enzyme
synthesizes a short stretch of RNA complementary to a part of the template DNA strand
The major alteration to DNA caused by ultraviolet light is
thymine dimer formation, an example of intrastrand cross-linking
DNA synthesis occurs in a _____ direction because the triphosphates of nucleotides are attached to the _____-hydroxyl group.
5´ 3´; 5´
A therapeutic window exists where chemotherapeutics such as cisplatin and cyclophosphamide can specifically kill cancer cells but not most normal cells in the body. Why do these drugs work?
They cause DNA-damage in all cells, but the damage can’t be repaired in cancer cells.
One of the biologically harmful effects of ultraviolet (UV) light is its action on DNA. UV light results in what alteration of DNA?
covalent formation of pyrimidine dimers involving adjacent pyrimidines in a DNA strand
