BIO 235 Exam 4 Questions and
Answers 100% Pass
Helicase - ✔✔Unwinds DNA in both directions
Gyrase - ✔✔topoisomerase that relieves supercoiling ahead of replication
fork
Single Stranded Binding proteins do what? - ✔✔Stabilize single stranded
DNA
Primase - ✔✔Enzyme that makes RNA primers
DNA polymerase cannot? - ✔✔Reconstruct the 5' end of a DNA strand
this poses problems for linear chromosome integrity
Telomeres - ✔✔Repetitive DNA sequences TTAGGG
1
100% Pass Guarantee Katelyn Whitman, All Rights
,-no protein coding
-binds two types
Two types of proteins that binds in telomeres - ✔✔-Protective proteins
-telomerase enzyme
Telomerase enzyme - ✔✔ribonucleoprotein
ribonucleoprotein - ✔✔composed of RNA and protein
Binding of telomerase to TTAGGG - ✔✔Addition of RNA extends ends
-carries its own DNA template as well....to finish DNA strand
Telomerase is key in determining what? - ✔✔Life-span of cell
Telomerase in immortalized cells - ✔✔ie germ line, cancer, yeast...
-Telomeres are fully reconstructed with each DNA replication
Telomerase in somatic cells - ✔✔Virtually absent
-shortened with every cell division
2
100% Pass Guarantee Katelyn Whitman, All Rights
, -somatic cells divide 30-50 times then die
in yeast, deletion of telomerase gene leads to what? - ✔✔Shortening of
chromosomes at each cell division
Telomerase activity in cancer cells? - ✔✔High activity
Telomerase activity in somatic cells which cancer derives? - ✔✔low activity
or absent
If you can block telomerase activity, you can do what? - ✔✔STOP
CANCER!
Nobel prize in medicine: - ✔✔Elizabeth Blackburn, Carol Greider, Jack
Szostak.
-Protection of chromosomes by the telomerase enzyme
DNA table characteristics - ✔✔-composed of nucleotides
-deoxyribose sugar
-A,G,C,T
3
100% Pass Guarantee Katelyn Whitman, All Rights
Answers 100% Pass
Helicase - ✔✔Unwinds DNA in both directions
Gyrase - ✔✔topoisomerase that relieves supercoiling ahead of replication
fork
Single Stranded Binding proteins do what? - ✔✔Stabilize single stranded
DNA
Primase - ✔✔Enzyme that makes RNA primers
DNA polymerase cannot? - ✔✔Reconstruct the 5' end of a DNA strand
this poses problems for linear chromosome integrity
Telomeres - ✔✔Repetitive DNA sequences TTAGGG
1
100% Pass Guarantee Katelyn Whitman, All Rights
,-no protein coding
-binds two types
Two types of proteins that binds in telomeres - ✔✔-Protective proteins
-telomerase enzyme
Telomerase enzyme - ✔✔ribonucleoprotein
ribonucleoprotein - ✔✔composed of RNA and protein
Binding of telomerase to TTAGGG - ✔✔Addition of RNA extends ends
-carries its own DNA template as well....to finish DNA strand
Telomerase is key in determining what? - ✔✔Life-span of cell
Telomerase in immortalized cells - ✔✔ie germ line, cancer, yeast...
-Telomeres are fully reconstructed with each DNA replication
Telomerase in somatic cells - ✔✔Virtually absent
-shortened with every cell division
2
100% Pass Guarantee Katelyn Whitman, All Rights
, -somatic cells divide 30-50 times then die
in yeast, deletion of telomerase gene leads to what? - ✔✔Shortening of
chromosomes at each cell division
Telomerase activity in cancer cells? - ✔✔High activity
Telomerase activity in somatic cells which cancer derives? - ✔✔low activity
or absent
If you can block telomerase activity, you can do what? - ✔✔STOP
CANCER!
Nobel prize in medicine: - ✔✔Elizabeth Blackburn, Carol Greider, Jack
Szostak.
-Protection of chromosomes by the telomerase enzyme
DNA table characteristics - ✔✔-composed of nucleotides
-deoxyribose sugar
-A,G,C,T
3
100% Pass Guarantee Katelyn Whitman, All Rights
