biotechnology. literally translated means “life technology” applying knowledge about living...
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Biotechnology
• Literally translated means “life technology”• Applying knowledge about living things for the
practical use of human kind • How long do you think biotechnology has
existed?
Buzz Words in Biotechnology
• Genetic Engineering• Stem Cell Research• Cloning• Bioterror• Forensic Science• GMO (genetically modified organsim)• Pharmacogenomics• Personalized Medicine• Human Genome Project
Place to following in order from smallest to largest
Atom Cell Ecosystem
Organ Organism Biosphere
Molecule (DNA)
Population Electron
Organelle Community Proton
Tissue Organ system Virus
Electron
Proton & neutron
Atom
Molecule (DNA)
organelle
virus
Cell
Tissue
Organ
Organ system
Organism
Population
Community
Ecosystem
biosphere
In Your Journal
Can all forms of technology be used to study all of these aspects of biology?Explain!
3 Main Types of Experiments
• in vitro: experiments done in glass, testubes, or petri dishes. Not in living multicellular organisms
• in vivo: in a living cell or organism• in silico: experiments done through computer
simulation or programming• Biotechnology demands synthetic thinking that
incorporates knowledge from all 3 types of experiments
Biotechnology
• The technical aspects of life involve the complex chemical interactions that take place among the several thousand different kinds of molecules found in any living organism
• Macromolecules in living things can be classified into 1 of 4 categories– Protein Nucleic Acid– Carbohydrate Lipid
Biotechnologies Macromolecules
Protein • Essential parts of organisms
that participate in virtually every process within cells. – Cell structure– Signaling– Transport– Biological catalysts– Immune response
Nucleic Acids• Contain the genetic
instructions used in the development and functioning of all known living organisms and viruses.
• 2 types :– DNA– RNA
Proteins: Essential Parts of Organisms
• Many proteins are enzymes that catalyze biochemical reactions and are vital to metabolism.
• Some have structural or mechanical functions– actin and myosin in muscle – proteins in the cytoskeleton maintains cell shape.
• Other proteins are important in cell signaling, immune responses, cell adhesion, and the cell cycle.
DNA: the Master Molecule
• Of the several thousand macromolecules needed to keep living things alive, DNA is the master molecule in whose structure is encoded all the information needed to create and direct the chemical machinery of life (mainly proteins)
DNA: the Master Molecule
• DNA accomplishes this by providing a template to make RNA, which in turn acts is the instructions to build proteins, which are essentially the building blocks and machinery that allow for life
• Analysis of the flow and regulation of this genetic information from DNA RNA Protein is the subject of molecular genetics
Molecular Genetics
• aka: molecular biology• Has blurred the lines between biology, physics,
and chemistry• It arose from a confluence of disciplines from
both the physical sciences and the natural sciences– Genetics Biochemistry– Physical chemistry Microbiology– Quantum mechanics Virology
Biotechnology & Molecular Biology
• Bio = Life– Molecular biology studies the relationship
between DNA RNA Protein• Technology :– Technology is a term with origins in the Greek technología • téchnē = 'craft' • logía = the study of something
Structure & Function
Natural scientists have always tried to find relationships between structure & function
This pursuit began with the examination of obvious physical attributes
Physicians from the earliest civilizations tried to relate their knowledge of the human body to the treatment of illness
Matthias Schleiden & Theodor Schwann
Advanced part of the cell theory in the 1830’s◦Individual cells are the basic units of structure
and function in both plants and animals Organs were now seen to be composed of tissues Tissues are groups of cells with similar structures
that perform similar functionsMoved structure functionalism beyond
systems directly observable with the naked eye
Determined all plants are made of
cells
Determined all animals
are made of cells
Cells
Cells in turn were found to be composed of organelles, each of which has its own specific function◦Mitochondria produce energy◦Lysosomes digest waste and cellular debris◦Ribosomes make protein◦Chloroplast do photosynthesis to make sugar
By the 1930’s the stage was set for structure functionalism to move to the level of biologically important molecules
4 Characteristics of Life
ReproductionOrganized structure composed of 1 or
more cellsThe ability to respond to your
environment and maintain homeostasisThe ability to transform energy
Molecular Biology
Molecular biology arose from the quest to define the nature of heredity
Reproduction is perhaps the most distinctive attribute of life
Replication of multicellular organisms all begin the same way, with replication of a cell
To explain replication of cells and inheritance of traits over successive generations is, in large measure, to define life
The Biotechnology Revolution
We now understand the nature of heredity and so have answered many of the questions of the genomic era
As we move into the post-genomic era the question is not about how things are inherited, but rather can we manipulate them!◦This is the subject of this class
Bear in Mind…
100 years ago there was no explanation why some siblings have brown eyes and other blue
75 years ago the physical structures of simple organic molecules were unknown
50 years ago we did not know the correct # of human chromosomes
25 years ago we did not know any of the genes behind cancer
We still do not know how many genes are in the human genome!
Heredity
Scientific study of heredity◦Heredity: the transmission of genetic characters
from parents to offspring: it is dependent upon the segregation and
recombination of genes during meiosis and fertilization
it results in the creation of a new individual similar to others of its kind but exhibiting certain variations
How are Traits passed on from 1 Generation to the Next
Enter Austrian Monk Gregor Mendel◦Crossed different varieties of garden pea plants
and using mathematical analysis provided a basis for inheritance
◦Brought the hereditary process down to the individual organism
◦Provided a mechanism to drive evolution
Types of Hybridization
P generation = parental generation◦True breeding parents
F1 generation = 1st filial or 1st generation of offspring
F2 generation = 2nd filial, or 2nd generation of offspring
Vocabulary
Gene: sequence of DNA that codes for a protein and thus determines a trait
Allele: 1 of a number of different forms of a gene
Gamete: A reproductive cell having the haploid number of chromosomes, especially a mature sperm or egg capable of fusing with a gamete of the opposite sex to produce the fertilized egg
Homozygous: pair of identical alleles for a traitHeterozygous: Having 2 different alleles for a traitGenotype: an organisms genetic makeupPhenotype: an organisms outward appearance
How are Traits passed on from 1 Generation to the Next
Mendel showed that “traits” are inherited in a predictable manner through what we now know are “genes”◦Genes governing individual traits do not
“blend” but rather are maintained as discrete bits of hereditary information
◦Useful traits can be accentuated through controlled mating
Mendels Hypothesis
1. Genes can have alternate versions called alleles.
2. Each offspring inherits two alleles, one from each parent
3. If the two alleles differ, the dominant allele is expressed. The recessive allele remains hidden unless the dominant allele is absent. from each parent
4. The two alleles for each trait separate during gamete formation
Mendelian inheritance has its physical basis in the behavior of chromosomes
Chromosome Theory of Inheritance◦States: Genes have specific loci (locations) along chromosomes, and it is the chromosomes that undergo segregation and independent assortment, rather than the individual genes
◦Developed in 1902 by Walter Sutton & Theodor Boveri
Thomas Morgan Hunt
Chose to use fruit flies as a test organism in genetics.
Allowed the first tracing of traits to specific chromosomes
There are many genes, but only a few chromosomes.
Therefore, each chromosome must carry a number of genes together as a “package”.◦Traits that are located on the same
chromosome, and so tend to be inherited together, are called Linked Genes
Linked Genes
All genes found on the same chromosome are said to be linked
If genes on the same chromosome are 100% linked, you would only produce the parental phenotype for that chromosome, and as you can see in the previous picture, that is not the case
Genetic Recombination
The production of offspring with combinations of traits that differ from those found in either parent
3 Types of Genetic Recombination◦Recombination of unlinked genes due to
independent assortment◦Recombination of linked genes due to crossing
over◦Recombination of genes due to human
manipulation
DNA: The Genetic Material
Learning about DNA contributes to our knowledge of…◦genetic disorders◦viral diseases◦cancer◦aging◦genetic engineering◦criminal investigations
Why its important
Objectives
Relate Griffith’s conclusions to the observations he made during the transformation experiments.
Summarize the steps involved in Avery’s transformation experiments, and state the results.
Evaluate the results of the Hershey and Chase experiment.
DNA
◦What does DNA stand for?
◦What subunits make up DNA?
◦What three parts do the subunits consist of?
deoxyribonucleic acid
nucleotides
phosphate group, Pentose (5 carbon) sugar, & a nitrogenous base
Friedrich Miescher
DNA was first identified as far back as ________ by a Swiss scientist named Friedrich ____________
He extracted DNA from the _________ of pus cells found on surgical bandages
At first DNA was called __________ because it was a substance found in the nucleus
1868Miescher
nuclei
nuclein
Miescher was also able to separate the substance into two basic parts…
◦The phosphate groups, also called phosphoric acid,were slightly acidic, so DNA belongs to a class of substances called nucleic acids
Throughout the next century, scientists made many exciting discoveries about the function and structure of DNA
Transformation
Griffith’s Experiments
In 1928, Frederick Griffith, a bacteriologist, carried out an experiment that led to an accidental discovery about DNA
He was actually trying to prepare a vaccine against the bacteria, Streptococcus pneumoniae, which causes pneumonia
Griffith was working with two strains of S. pneumoniae…◦One enclosed in a capsule of
polysaccharides, that protects the bacterium from the body’s defense system This helps make the bacterium virulent, or able to cause disease Smooth-edged S strain
◦The other strain lacks the polysaccharide capsule and is unable to cause disease Rough – edged= R strain
In Griffith’s experiment, he injected mice with…
◦ S bacteria
◦R bacteria
◦Heat-killed S bacteria
◦Heat-killed S bacteria and normal R bacteria
Note about “heat-killing”…
◦During Griffith’s time, it was not understood that DNA can tolerate temperatures around 90°C without being altered, but ___________ are altered at around 60°C
◦So “heat-killing” damages a cells proteins and _______________, but leaves DNA intact
proteins
enzymes
Somehow, the harmless R bacteria had changed and become ______________
Griffith had discovered what is now called ____________________◦Occurs when a cell picks up new DNA from it’s
_____________, changing its combination of genes, called a _________________
virulent
transformation
environmentgenotype
Heat-killed S bacteriais ____________ downand its DNA escapes to the environment
A receptor protein on the R bacteria receives the Sbacteria DNA
Receptor protein
broken
Then restriction enzymes _________ and _________ the two pieces of DNA together
Restriction enzyme
cut paste
But during Griffith’s time, scientists really didn’t understand transformation
During the 1940s and 1950s, scientists were still debating over what cell part contained genetic information◦Many scientists actually thought that
___________ contained our genetic information, and not DNA.
proteins
Oswald Avery In 1944, a scientist named Oswald __________
conducted a transformation experiment under 4 different conditions…◦ Condition 1: Added an enzyme that destroyed ________◦ Condition 2: Added an enzyme that destroyed ________◦ Condition 3: Added an enzyme that destroyed ___
Condition 4: Added an enzyme that destroyed ________ Result?
◦ Transformation was only stopped by the enzymes that destroyed DNA, so it must contain the genetic material!
Avery
proteins
DNA
lipidsCarbs
Despite Avery’s results, scientists remained _____________
Since proteins are so important to many cell _____________ and _______________, most scientists still thought that proteins contained the genetic material
skeptical
structures
metabolism
Hershey and Chase
In 1952, Alfred ___________ and Martha _____________ set out to settle the controversy.
Their experiments made use of a bacteriophage which is a type of virus that attacks and infect bacterial cells
◦ A virus is much smaller than a cell and consists of a nucleic acid. Either ________ or ________ (never both) surrounded by a protective protein coat called a
DNA
Capsid
HersheyChase
DNA RNA
capsid
A special type of virus that infects ________________ cells is called a __________________ or a _________ for short
The viral DNA is contained in the ________ and the tail __________ attach to the bacteria cell
After attachment, the DNA is injected into cell, almost like a _________
Capsid with DNA
Tail Fibers
bacteria
bacteriophagephage
capsid
fibers
shot
The bacteriophage made the perfect test subject, because it was a simple substance that contained both ________ and ____________
◦Scientists knew that DNA contained a ____________ group
◦They also knew that proteins often contain the element __________
DNA proteins
phosphate
sulfur
So Hershey and Chase labeled the phages with one of the following radioactive isotopes…
______, which wouldbe found in DNA
______, which would be found in the protein coat
32P
35S
These radioactive isotopes will __________ or break down into stable particles that can be ____________ with machines
Next the labeled phageswere allowed to ___________ the bacteria cells
decaydetected
infect
Hershey and Chase then checked to see which parts of the phage entered the bacteria cells
First the phages thatwere still attached tothe bacteria cells wereremoved with a__________________
blender
Then the bacteria cells and the phages were placed in test tubes and spun in a machine called a centrifuge
Which spins, causingthe different substancessettle out by _________weight
The heavier bacteria cells settled at the __________ of the test tubes while the lighter phages remained suspended in the supernatant at the top of the tube
Only the ______ isotope was found inside of the bacteria cells
35S test tube (protein)
32P test tube (DNA)
Bacteria cells
Phages35S
32P
bottom
32P
So based on these results… which substance, proteins or DNA, would you conclude is responsible for transformation?
35S test tube (protein)
32P test tube (DNA)
Bacteria cells
Phages35S
32P
DNA
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