Medical Biotechnology

Question 1

Gene Therapy

Answer 1

1)Introduction of genes into existing cells to prevent or cure a wide range of diseases

2)It is a technique for correcting defective genes responsible for disease development

Question 2

What are the two types of gene therapy?

Answer 2

Depending on which types of cells are being treated:

1)Somatic gene therapy

2)Germline gene therapy

Question 3

Somatic gene therapy

Answer 3

1)Transfer of a section of DNA to any cell of the body that doesn’t produce sperm or egg

2)Effects of gene therapy will not be passed onto the patient’s children

Question 4

Germline gene therapy

Answer 4

1)Transfer of a section of DNA to cells that produce eggs or sperm

2)Effects of gene therapy will be passed onto patient’s children and subsequent generations

Question 5

Concept of DNA, RNA and protein

Answer 5

1)Messenger RNA (mRNA) plays a vital role in translating the instructions in DNA into the proteins of life

2)If a gene is damaged it creates damaged mRNA, which goes on to create damaged proteins, and ultimately disease

3)Gene therapy will carefully select to correct the effect of a mutated gene that is causing disease

Question 6

Tools for gene editing

Answer 6

Vector-vehicles used in gene therapy to transfer the desired gene into a target cell

Question 7

2 main classes of vectors

Answer 7

1)Viral vectors

2)Non-viral vectors

Question 8

Viral vectors

Answer 8

1)Retrovirus vector system

2)Adeno virus vector system

3)Adeno associated virus vector

4)Herpes simplex virus vector

Question 9

Non-viral vectors

Answer 9

1)Pure DNA construct

2)Lipid noemulsions

3)DNA polymer conjugates

4)Human artificial chromosome

Question 10

Viral vs. Nonviral vector system (Definition)

Answer 10

1)Viral vectors are gene-delivery vehicles that deliver foreign genetic material into cells using a viral genome

2)Nonviral vectors are gene-delivery vehicles that deliver foreign genetic material into a cell by using inorganic, particles, lipid-based vectors, polymer-based vectors, and peptide-based vectors

Question 11

Viral vs. Nonviral vector system (Chemical, Biological, Physical Agent)

Answer 11

Viral vectors: Biological agent

Nonviral Vectors: Chemical agent

Question 12

Viral vs. Nonviral vector system (Biosafety)

Answer 12

Viral Vectors: Has risk to Biosafety

Nonviral Vectors: Has no risk to Biosafety

Question 13

Viral vs. Nonviral vector system (Efficiency and Specificity)

Answer 13

Viral Vectors: More efficient and highly specific

Nonviral Vectors: Less efficient and barely specific

Question 14

Single Dose/ Multiple Dose

Answer 14

Viral Vector: Single dose delivery sufficient

Nonviral vector: Multiple or repeated doses are required in delivery

Question 15

Medical Biotechnology-gene editing tools

Answer 15

1)DNA editing uses nucleases (molecular scissors)

2)Zinc finger nucleases (ZFNs)

3)Transcription activator-like effector nucleases (TALENs)

4)Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR)

Question 16

DNA editing using nucleases (molecular scissors)

Answer 16

Enzymes capable of cleaving the phosphodiester bond between nucleotides of nucleic acids

1)Exonucleases: digest nucleic acids from the neds
2)Endonucleases: act on regions in the middle of target molecules

Question 17

Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR)

Answer 17

1)CRISPR is a hallmark of bacterial defense system that forms the basis for CRISPR-Cas9 genome editing technology

2)CRISPR was first discovered in archaea, a bacterial immune system known to defend against invading viruses

3)CRISPR-Cas9 is a system that can be programmed to target specific stretches of genetic code and to edit DNA at precise locations

Question 18

How does CRISPR/Cas9 system work?

Answer 18

1)Target the right gene

2)Bind the target

3)Cut the DNA

4)Repair and edit the DNA

Question 19

1)Target the right gene

Answer 19

Scientists engineer a piece of RNA that is a match for the DNA they want to edit. This is called the guide RNA.

Question 20

2)Bind the target

Answer 20

An enzyme called Cas9 binds to a piece of DNA and temporarily unwinds a section of the DNA.

Question 21

3)Cut the DNA

Answer 21

If the guide RNA matches a section of the DNA, the Cas9 enzyme cuts both strands of the DNA double helix.

Question 22

4)Repair and edit the DNA

Answer 22

Machinery inside the cell rushes to fix the broken DNA. One repair process uses a similar-looking, unbroken piece of DNA as a template to stitch the broken pieces back together.

Scientists can introduce tailor-made DNA into the cell — tricking the repair machinery into using the engineered DNA as the template for stitching together the broken pieces.