BT corn, insulin - scientists have harnessed DNA from bacteria and humans to make new organisms and products. This is a good slideshow presentation for middle school and high school.
2. Normal corn vs. GMO corn...
What’s special about the GMO corn that causes
the caterpillars to die when they take a bite?
3. What is Genetic Engineering?
• All living things have DNA code
• Genes transferred from species to species, will produce the same product
Ex: scientists can take the gene for blue pigment from pansies and put it in
the DNA of roses. The genetically modified roses will grow blue petals.
• Scientists can cut, copy and paste DNA between species
4. Genetic Engineering has helped people with
diabetes.
When someone has Type 1 diabetes, their immune system attacks their
own pancreas, which produces insulin.
When someone stops producing insulin, they become very sick, and they
could die.
Doctors can give diabetic patients insulin so they can inject insulin in
themselves.
It used to be hard to get insulin. Scientists had to get it from cows, and
they would only get a little bit. This made it expensive.
5. Scientists found a way to trick bacteria to make
a lot of insulin.
• The genetic code is divided into segments called genes. Each
gene tells our cells how to make a protein. Proteins are the
machines that let our cells function. Insulin is also a protein.
• Scientists took the gene that codes for how to make insulin and
placed it into a bacteria cell.
• The bacteria read the code and started making insulin.
6. How did they put the DNA into the bacteria?
• Genetic engineers needed to cut DNA at specific places using
restriction enzymes.
• They use another enzyme called ligase to paste strands of DNA
together.
• Genetic engineers used E.coli bacteria. They take the human DNA
that codes for how to make insulin, and place it into the plasmid of
the bacteria. (Plasmids are small loops of DNA).
• The bacteria is tricked into making human insulin, and scientists are
able to quickly grow huge vats of E.coli bacteria that make tons of
insulin, inexpensively.
7. Genetically engineered food!
• Corn is also genetically engineered.
• Caterpillars ruin crops, so farmers have to spray insecticide to kill
them.
• Scientists found a naturally occurring bacteria called Bacillus
thuringiensis that produces a protein that’s toxic to the caterpillars.
• Scientists found the gene in the bacteria that codes for the poison
protein.
• They put the gene from the bacteria into the DNA of the corn.
• The new corn had corn DNA and bacteria DNA!
8.
9. How does it work?
1. The Bt gene is transferred from the Bt bacteria into the corn.
2. Every cell in the corn plant reads the modified DNA and
makes the protein toxic to caterpillars.
3. The caterpillars feed on the corn plant and swallow the
protein encoded by the Bt gene.
4. The Bt protein (poison) collapses the cells lining the
caterpillar’s gut and the insect dies.