BIOL 432 Midterm 1 Exam Questions with
100% Correct Answers
How does CRISPR work naturally? Correct Answer Clustered Regularly Interspaced
Short Palindromic Repeats
- bacterial defense mechanism
- bacteria have short palindromic repeats separated by spacer regions which are
segments of DNA from past viral exposure
- when attacked again by same virus, the spacer region is used as a template and the
guide RNA (tracrRNA) helps recognize the viral DNA and degrade it using Cas9
nuclease at the specific site
- need PAM (helps distinguish between self and non-self NA)
How do we use CRISPR? Correct Answer - make synthetic crRNA of the sequence/site
of interest and attach it to a tracrRNA using a linker loop
- crRNA-tracrRNA chimera basepairs with genomic DNA (next to PAM) and a double
stranded break occurs
- leads to NHEJ or HDR
NHEJ Correct Answer Non-homologous End Joining
- creates INDELS (insertion or deletion)
- leads to gene knockout by creating nick that isn't repaired properly
HDR Correct Answer Homology Directed Repair
- repairs cut with complimentary DNA (added)
- repair rate may increase many fold over
- leads to gene replacement
PAM - what, why and where Correct Answer - NGG sequence that differentiates
between host and foreign DNA
- next to target site/sequence
What is needed to modify chromosomal DNA using CRISPR? (4) Correct Answer - PAM
sequence
- ds or ss DNA
- DNA for gRNA
- Cas9
Main issues with CRISPR (4)? Correct Answer - off-site targeting
- ethical issues
- very had to get CRISPR to all adult cells
- also could develop cancer
Drug Development (describe stages briefly) (3) Correct Answer Discovery
, - millions compounds screened
- preclinical pharmacology (animals, pharmacokinetics - see where the drug goes)
- preclinical safety (animals, dosage)
- clinical pharmacology and safety
Exploratory
- Phase I (Safety)
Full Development
- Phase II (Dose) and Phase III (Effect)
FDA Review (Describe 3 Phases) Correct Answer Phase I - SAFETY
- between 10-100 healthy people, highest dosage assessed, for serious side effects use
individuals with the disorder of interest
Phase II - DOSAGE
- between 50-500 patients, optimal dosage determined, control group used to
distinguish between drug effects and natural remission and delineate real from apparent
side effects
Phase III - EFFECT
- 300-30 000 patients who have the specific disease, effectiveness proven
Amyloidosis Correct Answer - deposition of protein in an organ, cannot really be
removed
- some proteins can change conformation and cause other proteins to change
conformation
- different diseases have different proteins deposited
- multiple or one organ
Action of Kiacta on Amyloidosis Correct Answer Amino acids and GAGs interact to lead
to systemic amyloid A Fibril formation and deposition --> organ damage
- Kiacta blocks AA and GAG interaction which reduces fibril formation and deposition
Clinical Trial Costs Correct Answer - drug manufacturers estimate >$1 billion to develop
new drug including research and clinical trials and lost opportunity costs (actual costs
~$400 million)
- Canada is most expensive because of high regulation and bureaucracy, low
population makes it hard to recruit patients and coordinate
Why produce therapeutic agents using recombinant DNA? (4) Correct Answer - produce
large quantities
- cheaper
- amenable to create variants (mutagenesis)
- highly reproducible
100% Correct Answers
How does CRISPR work naturally? Correct Answer Clustered Regularly Interspaced
Short Palindromic Repeats
- bacterial defense mechanism
- bacteria have short palindromic repeats separated by spacer regions which are
segments of DNA from past viral exposure
- when attacked again by same virus, the spacer region is used as a template and the
guide RNA (tracrRNA) helps recognize the viral DNA and degrade it using Cas9
nuclease at the specific site
- need PAM (helps distinguish between self and non-self NA)
How do we use CRISPR? Correct Answer - make synthetic crRNA of the sequence/site
of interest and attach it to a tracrRNA using a linker loop
- crRNA-tracrRNA chimera basepairs with genomic DNA (next to PAM) and a double
stranded break occurs
- leads to NHEJ or HDR
NHEJ Correct Answer Non-homologous End Joining
- creates INDELS (insertion or deletion)
- leads to gene knockout by creating nick that isn't repaired properly
HDR Correct Answer Homology Directed Repair
- repairs cut with complimentary DNA (added)
- repair rate may increase many fold over
- leads to gene replacement
PAM - what, why and where Correct Answer - NGG sequence that differentiates
between host and foreign DNA
- next to target site/sequence
What is needed to modify chromosomal DNA using CRISPR? (4) Correct Answer - PAM
sequence
- ds or ss DNA
- DNA for gRNA
- Cas9
Main issues with CRISPR (4)? Correct Answer - off-site targeting
- ethical issues
- very had to get CRISPR to all adult cells
- also could develop cancer
Drug Development (describe stages briefly) (3) Correct Answer Discovery
, - millions compounds screened
- preclinical pharmacology (animals, pharmacokinetics - see where the drug goes)
- preclinical safety (animals, dosage)
- clinical pharmacology and safety
Exploratory
- Phase I (Safety)
Full Development
- Phase II (Dose) and Phase III (Effect)
FDA Review (Describe 3 Phases) Correct Answer Phase I - SAFETY
- between 10-100 healthy people, highest dosage assessed, for serious side effects use
individuals with the disorder of interest
Phase II - DOSAGE
- between 50-500 patients, optimal dosage determined, control group used to
distinguish between drug effects and natural remission and delineate real from apparent
side effects
Phase III - EFFECT
- 300-30 000 patients who have the specific disease, effectiveness proven
Amyloidosis Correct Answer - deposition of protein in an organ, cannot really be
removed
- some proteins can change conformation and cause other proteins to change
conformation
- different diseases have different proteins deposited
- multiple or one organ
Action of Kiacta on Amyloidosis Correct Answer Amino acids and GAGs interact to lead
to systemic amyloid A Fibril formation and deposition --> organ damage
- Kiacta blocks AA and GAG interaction which reduces fibril formation and deposition
Clinical Trial Costs Correct Answer - drug manufacturers estimate >$1 billion to develop
new drug including research and clinical trials and lost opportunity costs (actual costs
~$400 million)
- Canada is most expensive because of high regulation and bureaucracy, low
population makes it hard to recruit patients and coordinate
Why produce therapeutic agents using recombinant DNA? (4) Correct Answer - produce
large quantities
- cheaper
- amenable to create variants (mutagenesis)
- highly reproducible
