Objective: Chapter 13- Biotechnology

Biotechnology

• The use of organisms to perform practical tasks for humans.

Recombinant DNA Technology

• Putting a gene from one organism into another (plasmid). “AKA gene splicing”

PlasmidCircular piece of bacterial DNA that replicates

separate from the larger chromosome (in bacteria only)

Making a Recombinant DNA Molecule

• Restriction enzymes: found only in bacteria and is harvested to cut DNA at specific locations

How does it work?Human DNA DNA of Bacteria

How does it know where to cut?

Restriction enzymes recognize and cut (splice) the DNA only at specific nucleotide sequences

How does it work?

Once the DNA is cut, there are sticky ends:

Sticky ends: unpaired bases at the ends of the DNA where the enzymes have cut

DNA Ligase:

The “glue” that joins the 2 different DNA strands together

http://www.youtube.com/watch?v=x2jUMG2E-ic

Gene TherapyHuman DNA DNA of Bacteria

Genetically Modified Organism (GMO)

• Any organism that has aquired one or more genes by artificial means. (ex: a plant that contains a gene to delay ripening) http://www.youtube.com/watch?v=TpmNfv

1jKuA

Cloning

• A technique used to make genetically identical organisms called clones–Easy to clone bacteria, difficult to clone

multicellular organisms like animals

• First cloned mammal was Dolly, a sheep cloned in 1997

• Cloning humans raises serious ethical concerns (is it right or wrong?)

What happened to Dolly?

Dolly was the first organism that was successfully cloned.

Born: 1998Died: 2003Cause: lung

disease

SummaryWhat are the steps in cloning

a sheep?1. Take a nucleus from the

cell of one sheep2. Take an egg cell from

another sheep and take the nucleus out

3. Fuse the nucleus and the egg cell

4. Grow the cells5. Insert the cells in the

uterus of a foster mother

Do these cells look alike? Do they function alike?

Gene Expression

• Gene expression is the transcription and translation of genes into proteins (genes are “turned on” and a protein is made)

-All cells in the body have the same 30,000 genes on the same 46 chromosomes

Cellular Differentiation

• Cells become specialized in structure and function (heart cell, brain cell, lung cell)

Differentiation

Blastula

EmbryoEmbryo

Zygote

Stem Cells

• Undifferentiated Cells• Have the potential to differentiate into

various types of cells