Molecular Biology (Lectures 15-17)

What is the process in which fragments of DNA from each gene are "spotted" and immobilized on a glass microscope slide?

• A.

  DNA Microarray

• B.

  DNA Nanoarray

• C.

  SDS-PAGE

• D.

  2-D Gel Electrophoresis

Point mutation caused by UV light

Point Mutation that adds C-H alkyl group to N or O atoms.

Point mutation that causes transition mutations of C-G to T-A, by a mechanism where the Amino group spontaneously reacts with H2O to add O and generate ammonium (NH4+) Is ______________ and occurs roughly once every ________ base pairs per cell per day, and C-G is changed to _ - _ bp, then _-_ replicates:  T-A (mutation) and C-G (wild type)

Point Mutation in which incorrect bases are added by DNA polymerase, are not corrected by the 3'-5' exonuclease proofreading, and fall into the categories of "transversion" and "transition" mutations.

Removes purine bases, forming abasic sites, at a frequency of roughly __________ purines per cell per day

Enzyme found in plants, many bacteria, and some animals, that repairs thymine dimers, directly.

Which of the folowing are true about excision repair systems?

• A.

  Appear to repair the majority of mutations

• B.

  Appear to repair relatively few mutations

• C.

  Multiple, redundant types

• D.

  Only one known version

• E.

  Each deals with different kinds of point mutations

The type of Excision repair that fixes a damaged, single base is known as....

How does base excision repair perform?

Check all that are true about nucleotide excision repair (NER)

• A.

  Fixes damaged bases

• B.

  10-12 nucleotides removed

• C.

  Involves uvr genes

• D.

  Fixes damaged, single base

Which excision repair system fixes mismatches?

In humans, what type of repair system manages thymine dimers?

People with ___________  _________ (XP) have defective NER systems- at least eight different genes for NER.

Which of the following are true about Xeroderma Pigmentosum (XP)?

• A.

  They cannot repair bulky DNA damage (T-dimers, abasic sites)

• B.

  1000 times more likely to develop skin cancer

• C.

  Sun (UV) increases cancer in people with XP (T-dimers)

What are the two types of NER forms in Eukaryotes?

Both types of NER activate the same __________  _________ repair proteins.

___________   _____  when two non-pairing bases exist on complementary strands, involves mut genes in E.coli, and msh genes (mutS homologes) in eukaryotes.

Mismatch Repair Fixing Heteroduplex DNA: Problem: Which strand is correct and which strand has the mutated base? Solution: _________ of __ bases provides cues as to which strand is correct.

Some DNA in Bacteria is ____________ Helps in the repair of errors during replication.  "Old" DNA is ___________ (CH3) at A in 5'-GATC-3' About 10-20 min after replication, before "new" DNA strand is ___________ by "maintenance Methylase" Repair systems utilize this "Delay" to select old/correct strand (__________) from the new/defective strand (not  _________)

Photolyase is induced by....

Inducible repair system in E. coli (by mutagenic stress, T-dimers, etc.)

P53 is a ___________  _________  that activates: 1. ______________ 2. ______________ 3. ______________ (programmed cell death)

Inducible Repair SOS System in E. coli: DNA damage (________  _____) activates SOS Increases expression of ____ genes (error-prone bypass) Induction involves ______ that acts as protease to destroy _______ (transcription inhibitor)

____-__________ ____ ______ (NHEJ) System: "Ligates" ends of broken linear DNA (chromosomes) Important for repairing DNA breakage (ionizing radiation)