Biotechnology Flashcards
The Human Genome Project
Collaborative effort to map the location of the genes in a chromosome
Genome
Complete set of genetic information of an organism
Importance of the Human Genome Project
Can screen for genetic diseases, monitor gene expression - can be prevented through preventative drug treatment, lifestyle changes
Hereditary Diseases
Caused by defective genetic information transmitted from one generation to the next
DNA Sequencing
The determination of the precise order of nucleotides in a sample of DNA
Spastic Paraplegia
Affected Chromosome 2 - progressive limb weakness and stiffness; paralysis
Diseases screened through DNA sequencing
- Sickle cell anemia
- Cystic fibrosis
- Some cancers
Profiling Techniques
Gel electrophoresis
Steps in Gel Electrophoresis
- Restriction enzymes are used to cut DNA at particular sequence
- DNA pieces are placed on a semi-solid gel and an electric current is passed through
- Smaller pieces of DNA travel further than larger ones
- Unique banding patterns are formed
Polymerase Chain Reaction
Allows rapid duplication of DNA sample (amplification)
PCR Process
- Denaturation - heated to 96C, splits DNA
- Annealing - DNA is cooled, primers are added (complimentary DNA sections), join to form complimentary strand
- Extension - DNA polymerase duplicated complimentary strand; both complimentary and original strand used to create more DNA
Use of Taq polymerase over DNA polymerase in PCR
Doesn’t breakdown when heated above 37.5C; can be used during denaturation
rDNA technology
Introduction of foreign DNA into a cell; genes from one organism are added to the chromosomes of another organism
rDNA (genetic engineering) - insulin
- Identify & isolate the gene for insulin production using restriction enzymes
- Remove plasmid from bacterium, cut using restriction enzyme (acts as vector)
- Combine sliced plasmid and insulin gene, permanently join using ligase
- Transgenic plasmid replace into bacterium - undergoes mitosis
- Many transgenic bacteria are produced
- Transcription and translation of insulin gene produces insulin
rDNA (genetic engineering) - factor VIII
- Identify & isolate the gene for factor VIII production using restriction enzymes
- Remove plasmid from bacterium, cut using restriction enzyme (acts as vector)
- Combine sliced plasmid and factor VIII gene, permanently join using ligase
- Transgenic plasmid replace into mammalian cell - undergoes mitosis
- Many transgenic plasmids are produced
- Transcription and translation of insulin gene produces factor VIII
rDNA (genetic engineering) - vaccine
- Identify & isolate the gene for antigen from attenuated pathogen production using restriction enzymes
- Remove plasmid from bacterium, cut using restriction enzyme (acts as vector)
- Combine sliced plasmid and antigen gene, permanently join using ligase
- Transgenic plasmid replace into yeast cell - undergoes mitosis
- Many transgenic plasmids are produced
- Transcription and translation of antigen gene produces antigen
rDNA (genetic engineering) - human growth hormone
- Identify & isolate the gene for HCG production using restriction enzymes
- Remove plasmid from bacterium, cut using restriction enzyme (acts as vector)
- Combine sliced plasmid and HCG gene, permanently join using ligase
- Transgenic plasmid replace into bacterium - undergoes mitosis
- Many transgenic bacteria are produced
- Transcription and translation of HCG gene produces human growth hormone
Gene therapy
The transfer of a therapeutic (working copy) of a gene into specific cells of an individual to repair a faulty gene; easiest to treat point mutations
Gene therapy process
- Cells are removed from patient
- Virus is altered to inhibit reproduction (in vitro) using restriction enzymes
- Healthy copy of a gene is inserted into virus
- Altered virus is mixed with cells from patient
- Cells are genetically altered
- Altered cells reintroduced to host in lungs
- Cells begin to produce the correct protein
Gene therapy - viral vectors
Used to introduce DNA to a host cell, may be introduced in vitro or in vivo
Gene therapy - disadvantages of viral vectors
- Can only carry a limited amount of genetic material
- Can cause illness in patient
- Can be destroyed by immune system
Gene therapy - cystic fibrosis
Caused by faulty genes on chromosome 7
- Lung cells are removed from the patient
- Virus is altered in vitro to inhibit reproduction through the use of restriction enzymes
- A healthy CFTR gene is inserted into virus
- Altered virus is mixed with lung cells from the patient
- Cells become genetically altered
- Altered cells are reintroduced to host in lungs
- Cells containing CFTR gene produce the correct protein
Gene therapy - huntington’s disease
Caused by faulty genes on chromosome 4
- Nerve cells are removed from the patient
- Virus is altered in vitro to inhibit reproduction through the use of restriction enzymes
- A healthy huntington gene is inserted into virus
- Altered virus is mixed with nerve cells from the patient
- Cells become genetically altered
- Altered cells are reintroduced to host in brain
- Cells containing healthy huntington gene produce the huntington protein
Cell replacement therapy
Healthy cells derived from stem cells are introduced into the body - function in place of damaged cells
Embryonic stem cells
Harvested 4-6 day old blastocysts - are pluripotent
Cell replacement therapy - Parkinson’s and Alzheimers
Dying neurons can be replaced with healthy neurons derived from stem cells - neuro-degenerative diseases
Tissue engineering
Stem cells are induced to grow on a scaffold to produce a 3D tissue
Scaffold is then implanted into the patient where it is needed
Used for bone, skin, cartilage, adipose tissue
