What is the difference between mismatch repair and nucleotide excision repair? In
mismatch repair, one nucleotide is replaced, whereas in nucleotide excision repair several nucleotides are replaced
. You just studied 29 terms!
How does nucleotide excision repair differ from base excision repair quizlet?
Nucleotide-excision repair
reverses the chemical reaction that caused the lesion
, whereas base-excision repair removes the damaged bases and replaces them with normal ones.
What is the difference between mismatch repair and nucleotide excision repair?
The key difference between mismatch repair and nucleotide excision repair is that
nucleotide excision repair (NER) is used to remove pyrimidine dimers formed by UV irradiation and bulky helix lesions caused by chemical adducts
while mismatch repair system plays an important role in correcting misincorporated bases that …
What is the difference between BER and NER?
NER and BER are two types of DNA excision repair processes found in cells. BER is able to repair small damages caused endogenously while
NER is able to repair damage regions up to 30 base pair length caused mostly by exogenously
. … This is the difference between base excision repair and nucleotide excision.
Which type of repair is a backup for the DNA polymerase proofreading?
3.
Mismatch repair
: a) Provides a “backup” to the replicative proofreading carried out by most (but not all) DNA polymerases during DNA replication.
What are the steps in base excision repair?
The repair process takes place in five core steps:
(1) excision of the base
, (2) incision, (3) end processing, and (4) repair synthesis, including gap filling and ligation.
What happens in mismatch repair?
Mismatch repair happens right after new DNA has been made, and its job is
to remove and replace mis-paired bases
(ones that were not fixed during proofreading). Mismatch repair can also detect and correct small insertions and deletions that happen when the polymerases “slips,” losing its footing on the template 2.
What is the correct definition of nucleotide excision repair?
Nucleotide excision repair (NER) is
the main pathway used by mammals to remove bulky DNA lesions such as those formed by UV light, environmental mutagens, and some cancer chemotherapeutic adducts from DNA
. Deficiencies in NER are associated with the extremely skin cancer-prone inherited disorder xeroderma pigmentosum.
Which two of the following are types of DNA damage that are corrected by nucleotide excision repair?
Nucleotide excision repair is used to repair
deletions, insertions, and helix-distorting lesions
, such as thymine dimers.
What is the proper order of the steps involved in nucleotide excision repair?
- (i) recognition of a DNA lesion;
- (ii) separation of the double helix at the DNA lesion site;
- (iii) single strand incision at both sides of the lesion;
- (iv) excision of the lesion-containing single stranded DNA fragment;
- (v) DNA repair synthesis to replace the gap and.
Which enzyme is responsible for photoreactivation of DNA?
Photoreactivation is a light-induced (300–600 nm) enzymatic cleavage of a thymine dimer to yield two thymine monomers. It is accomplished by
photolyase
, an enzyme that acts on dimers contained in single- and double-stranded DNA.
What is the difference between DNA damage and mutation?
DNA damage is an abnormal chemical structure in DNA, while a mutation is a change in the sequence of base pairs. DNA damages
cause changes in the structure of the genetic material
and prevents the replication mechanism from functioning and performing properly.
How many types of excision repair system are known?
Three different types
of excision repair have been characterized: nucleotide excision repair, base excision repair, and mismatch repair. All utilize a cut, copy, and paste mechanism. In the cutting stage, an enzyme or complex removes a damaged base or a string of nucleotides from the DNA.
What is the effect on the DNA sequence if base excision repair does not remove the uracil and DNA replication is allowed to proceed?
It cleaves the DNA backbone in two places. In the example in the animation, uracil is incorrectly paired with guanine. What is the effect on the DNA sequence if base excision repair does not remove the uracil and DNA replication is allowed to proceed?
The original G−C base pair changes to an A−T base pair.
Which mutation in an animal somatic cell would be inherited by the next generation?
If a gene is altered in a germ cell, the mutation is termed a
germinal mutation
. Because germ cells give rise to gametes, some gamete s will carry the mutation and it will be passed on to the next generation when the individual successfully mates.
Are able to shift from one part of the genome to another?
Transposable elements (TEs), also known as “jumping genes,” are DNA sequences that move from one location on the genome to another. …
