Biotechnology. Early Biotechnology = using organisms or their cellular processes to improve the lives and health of people and the planet Has evolved

Biotechnology

Early Biotechnology

• = using organisms or their cellular processes to improve the lives and health of people and the planet

• Has evolved from using yeast in food products to selective breeding to DNA manipulation

which crosses

consists of

Selective Breeding

for example

Inbreeding Hybridization

Similar organisms

Dissimilar organismsfor

example

Organism breed A

Organism breed A

Organism breed B

Retains desired characteristics

Combines desired

characteristics

which

which crosses

which

Early Biotechnology

Copyright Pearson Prentice Hall

The Tools of Molecular Biology

• Scientists use different techniques to:• extract DNA from cells• cut DNA into smaller pieces• identify the sequence of bases in a DNA molecule• make unlimited copies of DNA



• DNA Extraction• DNA can be extracted from most cells by a simple chemical

procedure.• The cells are opened and the DNA is separated from the other

cell parts.



• Cutting DNA • Most DNA molecules are too large to be analyzed, so

biologists cut them into smaller fragments using restriction enzymes.



• Separating DNA • In gel electrophoresis, DNA fragments are placed at one end

of a porous gel, and an electric voltage is applied to the gel. • When the power is turned on, the negatively-charged DNA

molecules move toward the positive end of the gel.



• Based on size, the DNA fragments make a pattern of bands on the gel.

• These bands can then be compared with other samples of DNA.

Gel Electrophoresis


Using the DNA Sequence

• Making Copies • Polymerase chain reaction (PCR) is a technique that allows

biologists to make copies of genes. • A biologist adds short pieces of DNA that are complementary

to portions of the sequence.


DNA heated to separate strands

PCR cyclesDNA copies

1 2 3 4 5 etc.1 2 4 8 16 etc.

Polymerase Chain Reaction (PCR)

DNA polymerase adds complementary strand

DNA fragment to be copied


Cell TransformationRecombinant DNA

Host Cell DNA

Target gene

Modified Host Cell DNA


Transforming BacteriaRecombinant DNA

Gene for human growth hormone

Gene for human growth hormone

Human Cell

Bacteria cell

Bacterial chromosome

Plasmid

Sticky ends

DNA recombination

Bacteria cell containing gene for human growth hormone

DNA insertion


Transgenic Organisms

• Transgenic Microorganisms• Transgenic bacteria produce important substances useful for

health and industry. Transgenic bacteria have been used to produce:• insulin• growth hormone• clotting factor



• Transgenic Animals• Transgenic animals have been used to study genes and to

improve the food supply. • Mice have been produced with human genes that make their

immune systems act similarly to those of humans. This allows scientists to study the effects of diseases on the human immune system.



• Transgenic Plants • Transgenic plants are now an important part of our food

supply. • Many of these plants contain a gene that produces a natural

insecticide, so plants don’t have to be sprayed with pesticides.

A body cell is taken from a donor animal.

An egg cell is taken from a donor animal.

The fused cell begins dividing, becoming an embryo.

The nucleus is removed from the egg.

The body cell and egg are fused by electric shock.

The embryo is implanted into the uterus of a foster mother.

The embryo develops into a cloned animal.

Cloning

A donor cell is taken from a sheep’s udder. These two cells are

fused using a electric shock.

The fused cell begins dividing normally.

The embryo is placed in the uterus of a foster mother.

The embryo develops normally into a lamb—Dolly

An egg cell is taken from an adult female sheep.

The nucleus of the egg cell is removed.

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Biotechnology. Early Biotechnology = using organisms or their cellular processes to improve the lives and health of people and the planet Has evolved