Biotechnology Notes

Unit 3IN 81

Define Genetic Engineering

• Process where DNA is split into fragments and new DNA pieces are inserted

• Restriction enzymes cut DNA at certain places• Carriers are then used to insert DNA splices• Now referred to as recombinant DNA or

transgenicAnimation: http://www.hhmi.org/biointeractive/dna/animations.html

Applications of recombinant DNA• Bacteria: reduce frost

damage to crops, produce antibiotics

• Plants: resistant to herbicides, increase yield in crops

• Animals: cloning of endangered species, gene therapy,

Interesting Fact: About 40 different crops are approved for marketing in the US. That means 60-70% of the foods at your grocery store contain genetically engineered products! They are not labeled.

Stem Cells

• cells whose job in the body is not yet determined

• cell “turns on” specific genes in the stem cell to make them specialized

• For example, stem cells can become skin cells, bone cells, red blood cells, nerve cells, or skeletal muscle cells.

What are they used for?

• Repairing damaged tissue, replacing organs, treat Alzheimer’s or Parkinson’s diseases

What’s the big deal?

• Stem cells must come

from aborted or

miscarried fetuses

• Currently banned

Cloning• the creation of an organism

that is an exact copy of another

• occurs naturally in nature (identical twins)

• may be used for cloning stem cells, reviving endangered or extinct species, reproducing a deceased pet or child.

How is a clone made? • An early stage embryo is split

into cells before those cells have differentiated, the cells are then grown separately, and develop into identical embryos and can be implanted into surrogate mothers.

Conceiving a Clone!

• Try this science lab as a class:

• http://library.thinkquest.org/24355/data/createnav.html

Describe DNA fingerprinting

• Sample of DNA is exposed to restriction enzyme which cuts it into pieces

• DNA is loaded into a gel and run through electrophoresis machine

• Gel Electrophoresis Demo

• Since DNA is cut at certain sequences, each piece is a different length and weight

• Pieces that are heavier stay at the top of the gel, lighter will “run” to the bottom

• Every person is genetically different, so DNA fingerprints are different

DNA fingerprinting applications• Can be used to identify or eliminate suspects when

genetic material has been collected at a crime scene• Can be used to determine paternity of a child, or

establish other family relationships• Can be used to identify a deceased person

HOW DNA IS USED TODAY

–http://www.agresearch.co.nz/scied/search/tools/electro/activity_electro_fingerprinting_police.htm

C. Manipulating DNA

1. Scientists use knowledge of DNA to change DNA molecules

2. Techniques used to extract DNA, cut into smaller pieces and identify base sequences, make unlimited copies of DNA

3. Genetic engineeringGenetic engineering- making changes to DNA code and putting back into cell (by injection into cell, by bacteria, viruses)

V. Applications of Genetic Engineering

A. Transgenic organismsTransgenic organisms- contains genes from other organisms

1. Transgenic microorganismsTransgenic microorganisms- bacteria used to produce many important substances for health and industry (e.g. transformed bacteria now make insulin, growth hormone, clotting factor cheaply and in great abundance)

Transgenic tobacco plant- glows in the dark. Produced by transferring a gene from a firefly into a tobacco plant