Download Genetics

GENETICS
#whoareyou?
WHAT DOES A GENETICIST DO?


-
2 types:
Laboratory Geneticist
Genetics Counselor
Major fields for Geneticists include:
Medicine, Aquaculture, Crime & Pharmaceutical Companies
Uncover Origins of disease, birth defects & search for
Preventatives
EDUCATION
 Education Requirements: Bachelors in Biology or Chemistry
 Few positions with only a Bachelors
 Masters in Genetics helps but Ph.D or MD is required for REAL
advancements (money) power in research Facilities
WHERE CAN A GENETICIST WORK?


-


-
Universities:
lectures, Researchers, Technicians
Hospitals:
Genetic Clinicians Researchers, Technicians, Counselors &
Nurses
A gricultural, Pharmaceutical & Biotech Industries:
Researchers, technicians, management, writers, marketing &
Sales, Public Relations
Government:
Administrators, Managers, Of ficers —make policy regarding
Science, regulation, legislation
WHAT IS A MEDICAL FAMILY TREE?
 Preventive medicine as Physician can help identify
risks after ID of health problems
 Medical Family Tree Includes:
-
Recorded data about immediate family
Conditions that follow definite genetic pattern
Awareness to avert advanced disease/disability
Age of individual when disease 1 st occurred
Occupations that may expose workers to factors that affect
health
- History of GOOD health (important?)
MEDICAL FAMILY TREE

-
Chromosomal Abnormality Testing:
Birth records
Apgar score
Rates of newborn respiration
Muscle tone
Reflexes
Heart rate
Color on scale of 0-10
Chronic Villus Sampling
MEDICAL FAMILY TREE






Incomplete pregnancies
Record of immunizations of each family member
Medical exams & tests done
Individual problems, medications, allergies
Physical characteristic of family members
Records of family illness, accidents, surgical procedures
- Common childhood illness/diseases
MEDICAL HISTORY FAMILY TREE: SAMPLE
WHAT IS A CELL?
How does a Cell pertain to Genetics?
Cell: the basic building blocks of all living things
Each part has a dif ferent function
Organelles: perform special tasks within a cell
Major Parts of Human Cells:
Cytoplasm: fluid inside cell—surrounds organelles
Endoplasmic Reticulum (ER): smooth & rough: organelle helps
process & transplant molecules into/out of cell
⁻ Golgi Apparatus: packages molecules processed by ER to be
transported
⁻ Lysosomes: organelles—recycling waste center of cell. Digest
foreign substances/worn-out cell components





⁻
⁻
CELLS & GENETICS
 Mitochondria:
⁻ Organelles that act as energy power stations to convert
energy from food to form cells can use: has mitochondrial
DNA: can copy self. Maternally inherited.
 Nucleus:
⁻ Cells Command Center; tell cell when to grow, mature, divide,
die. Houses DNA Surrounded by membrane
 Cell/Plasma Membrane:
⁻ Outer lining of a cell; separates cell from environment; how
substances enter and leave cells
 Ribosomes:
⁻ organelles act as productions line to process cell’s genetic
instructions to create protein
CLASSES OF PROTEINS


-


-
Amino Acids:
Building blocks of all proteins
Enzymes:
Proteins that are catalysts to increase the rate of chemical
reactions
Structural Proteins:
Provide shape & support to organelles
Regulatory Proteins:
Control cellular functions
PROTEINS—WHAT THEY DO






Provide structure & support for cells
Insure that food reaches cells
Insure nervous impulse transmission
Protect from invaders
Enable chemical reactions to occur in body
Enzymes—proteins that act as catalysts
GENE EXPRESSION
 What is a Nucleic Acid?
- DNA & RNA are major nucleic acids. They store, transmit, and
express genetic information
- Tongue Roll?
- Eye Color?
- Ear Lobes?
- Dimples?
- Hand Clasping? Right over Left? Left over Right?
DNA
 Discovered in 1952 by Watson, Crick, Wilkins &
Franklin; but Nobel Prize only was given to
Watson & Crick
 DNA is located in the nucleus & must be
replicated before a cell can divide
 Since DNA cannot leave the nucleus, it must be
transcripted into RNA
CENTRAL DOGMA
 The Central Dogma:
 DNA encodes the information to make RNA….and RNA
molecules function together to make protein
 How do DNA and RNA dif fer?
- Sugar in DNA is Dexyribose in RNA it is Ribose
- The nitrogenous base uracil is used in RNA in place of
thymine (in DNA)
INTERACTIVE VIDEOS
 http://www.youtube.com/watch?v= -CoY7-riEUI
http://www.youtube.com/watch?v=ezSEAh3qHgw
DNA UNWINDING & TRANSCRIPTION
 DNA is transcribed or re -written into RNA in a very
complicated process called transcription
 The double helix is unwound and each strand acts as a
template.
 Bases are matched into synthesize and new partners strands.
 DNA begin to starting point for DNA replication while Helicase
is the enzyme that unwinds the DNA helix
 Rungs of the DNA ladder must split down the middle and pull
apart by binding RNA polymerase, an enzyme that makes RNA
from DNA .
 The 1 st step in protein production is Transcription; which takes
place in the nucleus; DNA is the blueprint for RNA
STEPS OF TRANSLATION
 Initiation mRNA enters the cytoplasm and becomes associated
with ribosomes (RNA + proteins)
 tRNAs, each carrying a specific amino acid, pair up with the
mRNA codons inside the ribosomes. Base pairing between mRNA
codoms and tRNA anticodons determines the order of amino
acids in the protein
 Elongation: addition of amino acids one -by -one
- As the ribosome moves along the mRNA and the tRNA transfers
its amino acid the growing protein chain, producing the protein
- Termination: when the ribosomes hits a stop codon; the
ribosomes falls apart
- The same mRNA may be used hundreds of times during
translation by many ribosomes before it degraded (broken -down)
by the cell
STEPS IN TRANSLATION
RNA & PROTEIN
 The order of the bases in the DNA specifies the order of
bases in mRNA
 The order of bases in the mRNA specifies the order of amino
acids in protein
 Both DNA & RNA are assembled from nucleosides
triphosphates or nucleotides (TP=triphosphate)
 For DNA they are: dATP,dCTP, dGTP, & dTTP
 For RNA they are: ATP, CTP,GTP, & UTP
STRANDS & DIRECTIONS OF SYNTHESIS
 DNA normally has two strands; the sense strand and the
antisense strand
 The double-stranded DNA , only one strand codes for the RNA
that is translated into protein.
 This DNA strand is referred to as the antisense strand.
 The sense strand that does not code for RNA is called the
sense strand.
 Antisense DNA; strand of DNA that carries the information
necessary to make proteins by binding to the corresponding
messenger RNA .
 Although these are MIRROR IMAGES, only the antisense
strand contains the information for making proteins
 Antisense strand is known as noncoding DNA
FORMS OF GENE THERAPY/GENETIC
ENGINEERING
 Scientists use Restriction enzymes to clip a DNA chain at a
specific point and insert another piece of DNA chain from
another cell; then rejoin with another enzyme w/new
characteristics
 This is called Recombinant DNA or Gene Splicing. And the
process of Polymerase Chain Reaction is how it occurs.
 PCR allows researchers to crate millions of copies of a
specific DNA sequence in two hours
 Gene Splicing:
- Aka antisense technology
where by a gene that may
cause disease can be
inactivated.
- Used to treat viruses including
AIDS, Herpes, Hepatitis &
Chicken Pox's
 Genetic Engineering:
- Replacing gene components in
order to encourage replication
of desired traits
- Used in animals and plants
- Used to increase productivity,
control weeks and insects, and
preserve diversity within the
ecosystem
POLYMERASE CHAIN REACTIONS (PCR)
 To amplify a segment of DNA using PCR, the sample is:
- Heated so the DNA denatures (separates) into two pieces of
singe-stranded DNA
- Then an enzyme called “Taq Polymerase” builds two new
strands of DNA; using the original strands as templates.
- This process results in the duplication of the original DNA ,
with each of the new molecules containing one old and one
new strand of DNA .
- These strands can be sued to create two new copies, and so
on
USES?
 Diagnoses Genetic Disease
 Carry out DNA fingerprinting:
- used in paternity
- maternity cases
- criminal ID , personal ID
- diagnosing Inherited disorders
- classifying immigrants
 Detect bacteria or viruses
 Research human evolution
 Clone DNA of Egyptian mummy
 Etc….
WHAT IS THE HUMAN GENOME PROJECT?
 13 year project between US Dept. of Energy & Natural
Institute of Health
 GOALS:
- Identify the 25,ooo genesis human DNA
- Determine sequences of the 3 billion chemical base pairs
making up human DNA
- Store information in databases
- Improve tools for data analysis
- Transfer related technologies to the private sector
- Address ethical, legal & social issues that come up; cloning
BIOTECHNOLOGY & “GENETICALLY MODIFIED”
 These names are interchangeable
− Genetically modified: means altering living organisms
− Biotechnology: living organisms such as enzymes to make
better products; cheese, beer, etc.
COMMERCIAL APPLICATION OF
RECOMBINANT DNA
 Making Insulin
 Interferon:
− Natural defense against viral infections and certain types
of cancer
 Factor VII & IX—clotting factors needed by hemophiliacs
 Human Growth Hormone:
− Used to treat dwarfism
 Flavor-Saver—keep fruits/veggies fresh longer
 Gene Therapy:
− Fixing specific diseases by replacing one defective gene