Biotechnology

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

Molecular Biology Arises From a

Structure-Function Tradition

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.

New Vocabulary

VaccineVirulentTransformationBacteriophage

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

Griffiths Discovery of Transformation

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

Time Line

1866- Mendel's Paper1875- Mitosis worked out1890's- Meiosis worked out1902- Sutton, Boveri et. al. connect

chromosomes to Meiosis.1907- Morgans “fly room” provides

support for chromosomes as the hereditary material