Tuesday, April 15, 2008

Genetic Engineering/DNA technology


Genetic Engineering 

involves removing a gene from one organism or living thing and placing it into another organism. This is done so that the organisms with the new gene can make the gene's product. For example, a human insulin gene can be removed from a human chromosome and then inserted or placed into bacteria, and now because the bacteria has the gene for insulin, the bacteria can make insulin.  

The bacteria do not use insulin, they pass it out as waste product and humans extract or collect the insulin and use it for people who suffers with diabetes.

Remember,
a gene is information on how to make a protein. Once the organism has the gene, it can make the protein.



 
Transgenic organisms
are organisms with functional foreign genes.

If you place a human gene into bacteria, then the bacteria will make a human protein.


A gene is information on how to make a protein.

Click here to view GENETIC ENGINEERING ANIMATION
Questions and Answers

Identify two molecules that can be made using genetic engineering
  • Insulin and growth hormone

 List two ways that people benefit from genetic engineering.
  • People who are diabetic can now take insulin that is produced through genetic engineering and also, youngsters who are not producing growth hormones are able to take growth hormones produced by this technique.

What role does insulin play in the body?
  • Insulin lowers blood sugar level (It does this by converting glucose into a storage form called glycogen and glycogen is stored in the liver.)

What organ or endocrine gland produces insulin?
  • Insulin is produced by the pancreas.
Another hormone called glucagon is antagonistic or works to reverse the action of insulin by raising blood sugar level. (Glucagon converts glycogen back into glucose and the glucose is release into the blood.)

Restriction Enzymes

are bacteria enzymes that cut double stranded DNA at a specific locations called restriction sites. These restriction sites are found on the non-coding regions of the DNA sometimes referred to as junk DNA . The locations of the restriction sites are different for different individuals. Because we inherit our DNA and therefore our restriction sites from our parents, when using the same restriction enzymes, the cuts are made at similar locations for people who are closely related.

Animation of Restriction Enzymes


NOTE: In order to remove a human gene from the human chromosome, it is necessary to cut the gene out of the chromosome and this is done using a restriction enzyme.

ADDITIONALLY: In order to place a human gene into bacteria, it is also necessary to cut the bacteria's DNA using the same restriction enzyme that was used to cut the human gene. Another enzyme called ligase is used to join or splice the human gene to the bacteria's DNA.



RESTRICTION ENZYMES
are the cutting tools in genetics.
IN FORENSIC ANALYSIS: In forensic analysis/crime scene investigation, restriction enzymes are used in conjunction or together with another technique called "gel electrophoresis".

Treating DNA with restriction enzymes results in fragments or pieces of different sizes.


GEL ELECTROPHORESIS is method that is used to separate molecules based on their sizes and charges. This technique creates a banding pattern or stains based on the size of the fragments or pieces in the sample used.  This technique is used in forensic analysis to include or exclude a person as a potential suspect.  It is used to establish identification.  Additionally, it is used to determine relationship.  For example, it is used to determine paternity.

GEL ELECTROPHORESIS LAB 1

Gel Electrophoresis Virtual Lab

People who are closely related, their DNA will create similar banding pattern on the gel electrophoresis. This is because the pieces that are generated by the enzyme are of similar sizes.

ONLINE CRIME SCENE INVESTIGATION

Designer Babies Video
 
 
Check this cloning interactive

OTHER METHODS THAT ARE USED AS MOLECULAR EVIDENCE TO DETERMINE RELATIONSHIP ARE:

  • Enzyme test
  • Paper chromatography is a technique used to separate pigment into individual colors.
  • Amino acid sequence
  • DNA sequence


Questions

  • List two ways that we benefit from genetic engineering
  • What is gel electrophoresis?
  • In the Biodiversity Lab, what laboratory tools are used in place of restriction enzymes?
  • What is the purpose of placing a human gene into bacteria?

Answers
  • We benefit in medicine and in agriculture.
  • Gel electrophoresis is a technique used to separate molecules by size.
  • In the biodiversity lab, scissors are used in placed of restriction enzymes.
  • We place human gene into bacteria so bacteria can make human protein.

List one genetic disease.
• Sickle cell


Identify a technique, which can be used to diagnose this disease
• Gel electrophoresis


List one chromosomal disease.
Down syndrome


Identify a technique, which can be used to diagnose this disease
Karyotype


CLICK HERE TO SEE ANIMATION OF KARYOTYPE

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