Transcript Madam I`m Adam

Biotechnology
• Gene: The unit of inherited information in
DNA.
• Gene Splicing: Using restrictive enzymes to
cut DNA and add new base pairs.
• Recombinant DNA: Combining genes from
different sources—even different species—
into a single DNA Molecule.
The Importance of Palindromes to
Genetic Engineers
The sites where restriction enzymes cut the bacteria
plasmid are called the restriction sites. Scientist
recognizes these sites because they are palindromes.
For Example:
5’ A A T G G C C A T T 3’
3’ T T A C C G G T A A 5’
The Origins of Restriction Enzymes: Scientist obtain
restriction enzymes from bacteria. In nature bacteria
normally use these enzymes to restrict the invasion of
foreign DNA, cutting the foreign DNA up into small,
functionless pieces.
Function of Restriction Enzymes: Restriction
enzymes are used as chemical “scissors” to cut out
genes.
Ligase: An enzyme. The mechanism of DNA
ligase is to form covalent phosphodiester bonds
between 3' hydroxyl ends of one nucleotide with
the 5' phosphate end of another.
http://www.dnalc.org/ddnalc/resources/restriction.html
Genetic Engineering can be Harmful
•New Allergens in the Food Supply
•Antibiotic Resistance
•Production of New Toxins
•Concentration of Toxic Metals
•Enhancement of the Environment for Toxic Fungi
•Unknown Harms to Health
Genetic Engineering can be Helpful
•Increase in the Food Supply
•Production of insulin and other human hormones.
•Development of effective vaccines against disease
causing microbes.
•Production of natural pesticides
Antibiotics are used to detect the
transformed plasmids
Some plasmids carry resistance genes to
several antibiotics.
The antibiotics that worked to select
transformed bacteria
Ampacillin Resistance
Tetracycline Resistance
Kanamycin Resistance
Proteins that are currently Produced using
Genetic Engineering
Human Insulin
Vaccines
Human Growth Hormone
Other Uses of Restrictive Enzymes
Disease Resistant Organism
Medical Research
Insect Resistant Plants
Larger Crops
Larger- Nutritionally Enhanced Food
Gene splicing is just what it sounds like: cutting the DNA
of a gene to add base pairs. Contrary to the immediate
image, however, no sharp instruments are involved;
rather, everything is done chemically.
Bioethics
The study of ethical problems arising from scientific
advances,
especially in the fields of biology and medicine.
Examples of Some Bioethical Issues
Assisted Suicide
Abortion
Birth Control
Growth Hormones – Performance Enhancement Drugs
In Vitro Fertilization
Pre-Implantation Genetic Diagnosis
Genetic Modification – Genetic Engineering
Cloning
Stem Cell Research
Pre-Implantation Diagnosis - PGD
Pre-Implantation Diagnosis - PGD
The pre-implantation genetic diagnosis (PGD) genetic testing
procedure begins with in vitro fertilization. Embryos are formed
in the lab, and then biopsied so cells can be used for genetic
testing. The DNA codes of the diseases that PGD can screen for
are then compared to the codes of each embryo. Only embryos
with normal biopsy results free of genetic defects are used for
implantation.
Diseases Detected with PGD Genetic Testing
Pre-implantation genetic diagnosis checks for genetic and
chromosomal abnormalities that cause birth defects and miscarriage.
This genetic testing procedure can identify recessive sex-linked
disorders, dominant sex-linked disorders, single sex gene disorders,
and chromosomal rearrangements.
Stem Cells
•Totipotent Cell: Formed during reproduction, a single cell
(zygote: fertilzed egg) that divides to produce all the differentiated
cells in an organism, including extraembryonic tissues.
•Pluripotent Cell: stem cell that has the potential to differentiate
into any of the three germ layers: endoderm (interior stomach
lining, gastrointestinal tract, the lungs), mesoderm (muscle, bone,
blood, urogenital), or ectoderm (epidermal tissues and nervous
system). Pluripotent stem cells can give rise to any fetal or adult
cell type.
•Multipotent Cell: progenitor cells can give rise to several other
cell types, but those types are limited in number. An example of a
multipotent stem cell is a hematopoietic cell — a blood stem cell
that can develop into several types of blood cells, but cannot
develop into brain cells or other types of cells.
Unipotent Cell: Can give rise to only one type of cell.
Adult Stem
Cells
Multipotent
Cells
From Bone Marrow
Adult Stem Cells
From Umbilical Cord
Embryonic
Stem Cells
Stem Cell Development
1. Zygote: A fertilized egg.
2. Morula: A solid ball of 2-16 embryonic cells.
3. Blastula: A hollow ball of several hundred embronic cells.
4. Gastrula: Blastula pushes inward forming an inner
embryonic cell layer.
5. Ectoderm: Outer embryonic cell layer. Skin, nervous system
6. Mesoderm : Middle embryonic cell layer. Muscle, bone.
7. Endoderm: Inner embronic cell layer. Digestive system.
Modeling Stem Cell Development
Zygote
1 Cell
Fertilized Egg
Morula
Before 3 Days
1-16 cells
Blastula/Blastocyst
3 - 14 Days
Several Hundred Cells
Gastrula
After 14 Days
Several hundred and More
• ECTODERM: Skin, Hair, Nails, Nervous
System, Brain
• MESODERM: Muscles, Circulatory
System, Excretory System, Bones, and
Cartilage, Gonads
• ENDODERM: Digestive and Respiratory
Tract, Glands including liver and pancreas,