Biotechnology Tools
SBI 4U: Molecular Genetics
What are biotech tools?
Introduction
Allow biologists to cut, join, and replicate DNA
- Allow biologists to take specific sections of DNA and move them from one DNA molecule to another, forming recombinant DNA
- Allow biologists to analyze sequences of DNA to determine relationships and identify organisms
Restriction enzymes
Restriction Enzymes
Endonucleases that cut DNA at specific, usually palindromic, recognition sites
- In English: "Madam, I'm Adam"
- In DNA: GAATTC (complementary sequence: CTTAAG)
Blunt & Sticky Ends
Different enzymes cut DNA in different ways
- Blunt ends: cut is made straight through DNA - no bases overhang
- Sticky ends: cut zigzags through DNA, leaving complementary bases on one strand overhanging the other
Ligase
Two strands of DNA cut by the same restriction enzymes will have the same sticky ends
- The same complementary bases will be exposed
- They will form complementary base pairs with each other
- They can be glued together, forming a new sequence... this is recombinant DNA!
Example: BamHI
- B: Genus Bacillus
- am: Species amyloliquefaciens
- H: strain
- I: Roman numeral 1 - first restriction enzyme isolated from this strain
Why don't the bacteria's enzymes cut its own DNA?
Self-Preservation
Methylases are enzymes that add a methyl group to one of the nucleotides in a recognition site, altering its chemical composition
Transgenic Organisms
Genetically Modified Organisms
- Contain DNA from different species
- Engineered to provide some benefit
Follow the instructions to bioengineer a (paper) bacterial plasmid that contains a gene for producing human insulin!
Paper Lab: Simulating Recombination
Glow in the Dark Animals... Why????
https://news.nationalgeographic.com/news/2009/05/shining-for-science-pictures-of-glowing-animals/#/090514-01-glowing-jellyfish_big.jpg
Glow in the Dark
- A visible indicator of success that has no negative effects on the organism
- Paves the way for understanding how to transfer other genes - those that might have a medical benefit to humans
- The glow in the dark fish are sold as pets
Genetically Modified Organisms in Food
https://globalnews.ca/news/5151706/explainer-genetically-modified-food-non-gmo-labels/
Foods
Transgenic Animals
Animals
Spider Goats
Spider Goat
Silk can be used for fishing line, surgical sutures, bulletproof vests, skin repair (burn victims), etc.
Transgenic Cows
https://www.sciencelearn.org.nz/resources/834-transgenic-cows-introduction (scroll down to second video)
Polymerase Chain Reaction
A method of increasing the amount of DNA of interest (i.e. a single sequence or gene)
PCR
Molecular Identification
- DNA Fingerprinting
- Classification of organisms
- Prenatal diagnosis
- Mutation screening
- Genetic matching
- Detecting pathogens
Sequencing
Bioinformatics
Genomic cloning
Human genome project
Sequencing
Genetic Engineering
Site-directed mutagenesis
Gene expression studies
Genetic Engineering
Gel Electrophoresis
Method of comparing DNA from different sources
- Produces a DNA "barcode" or "fingerprint"
Gel Electrophoresis
Gel Electrophoresis Virtual Lab
https://learn.genetics.utah.edu/content/labs/gel/
Virtual Lab
Loading the gel
Science Centre Workshop
CRISPR
Origin: naturally occurring proteins in prokaryotes
- like an immune system - detect and destroy viral DNA
Biotech application: targeted genome editing
- Can cut out and replace specific sections of DNA
CRISPR
The Nature of Things
Make jot notes or a t-chart to list some advantages/applications and some dangers/concerns of this technology
The Genetic Revolution