Download LIFE: ITS CHARACTERISTICS AND STUDY Biology is the study of

LIFE: ITS CHARACTERISTICS AND STUDY
Biology is the study of living things. The definition is easy, but the
science of biology is very complex, because even a single cell is very
complex. And each human being contains trillions of cells. But all the
scientific facts apply to these living systems.
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The laws of motion
Energy conservation
The laws of electricity and magnetism
Chemical bonding of atoms
These operate and govern the behaivour of all living things.
In some ways, biology is the most demanding of all sciences partly
because living systems are complex and partly because biology is a
multidisciplinary science that requires a knowledge of chemistry,
physics and maths.
It is the one that is most connected to the humanities and social
sciences among the other natural sciences.
The complexity of life is amazing, but it can be overwhelming. To
help you keep from getting lost in the forest because of all trees, we
will go step by step.
An ant provides a useful way to begin thinking about biology and
living things.
We can study it in many ways:
We can, for example, examine it as an individual organism...
...and ask: How big is it?
How much food does it consume?
Where does its energy come from?
At a more microscopic view; consider the individual ant as a
collection of specialized organs:
How does ant move the oxygen from the air to its cells?
How its outer hard covering protects it?
Deeper: We can look at the ant as a collection of cells, consider
how a single one of those cells operates...
How does the cell carry out its chemical functions?
What are the pieces in this cell?
...look inside the cell, think about its ultimate parts
The atoms and the molecules that combine & react
chemically.
What are the molecules that operate in a cell?
How do they interact as chemicals?
We could also look at the big picture. We can think of ant as a
part of larger & larger structures.
A single ant → social organization of an ant colony
which forms the ecosystem, in a forest e.g.
So you can study a single living thing in many levels.
Different branches of biology deals with these levels.
In the classical biology until 19th century, scientists tried to only
categorize the living systems. Then after, they started to study the
molecules in our bodies. In the 1950s, scientists discovered
deoxyribonucleic acid (DNA). And this discovery opened up an entire
new world in life sciences. Today, a majority of biologists study the
living systems on molecular level.
Unity within diversity:
1. All living things have a high degree of order & complexity. (ranking
from the simplest object to the most complex one)
2. All living things are part of larger systems of matter & energy.
(matter & energy recycles through the environment)
3. All life depends on chemical reactions that take place in cells
(most living things share a basic set of molecular building blocks
and chemical reactions) and there are some specific reactions.
Cells are the chemical factories of life, highly organized building
block, many organisms such as bacteria and blue-green algae are
single-celled whereas humans have trillions of cells.
4. All require water as solvent and temperature regulating medium.
5. Organisms grow and develop.
6. Living things regulate their use of energy and respond to their
environment:
During extreme cold or hot (dryness), for example, many plants
will lie still and animals will become sluggish.
When you are hot, you sweat and lose heat as sweat evaporates
from your body.
When you are cold, you shiver and shake and generate heat by
your muscles.
7. All living things share the same genetic code which is passed from
parent to children. The genetic secret is kept in DNA.
8. All living things on the Earth are descended from a common
ancestor.
Biology is the study of living things:
Complex system
Interdisciplinary
Organization
Structures:
of
living
things
/
Biological
Organism → organ → tissue → cell → organelle →
supramolecular assembly → macromolecule (DNA, RNA,
protein…)
Biology has not only grown, but essentially changed during
the last 50 years, from a science that describes & catalogs
the natural world to one that provides a detailed explanation
of the mechanics of the natural world.
The transformation has changed the ways in which biology
is studied…
Hierarchical organization
Voet and Voet, 1995
Biothechnology
Broad Definition
Any technology that utilizes biological systems (living
organisms or cells) or components of a living system
(antibodies, enzymes, DNA) for the goal of product
manufacturing or to solve research problems.
Modern Applications of Biotechnology include:
The Human Genome project
Gene therapy
Diagnostic testing for disease
DNA forensic Testing
Agricultural Biotechnology
Biosensors
Bioremediation
Biomedial Applications •
Immuno and protein therapy
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Drug Discovery
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Vaccine development
Microelectronics and
Information Technologies
Microelectronics and
Information Technologies
CAD
Electronic measurements
Control engineering
Biotechnology
New techniques for
material syntheses
CAD
CAM
Data manipulation
Databases
Internet
Measurement
New equipment
New Materials
Biochips
Biosensors
Artificial intelligence
Superconductors
Advanced ceramics
New Semiconductors
Nanotechnology
Optical Fibers
Composites
Biotechnology
New Materials
Membranes
IMPORTANT TECHNOLOGIES FOR THE FUTURE (US)
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Biotechnology
High performance computing and communications
Materials Science
Molecular Biology
Cognition / Neurobiology
Space Science
Environmental technologies / Sustainable development
Educational Technologies
For any technology to be called a REVOLUTIONARY
TECHNOLOGY it must have major, long term, economic and social
technology.
According to Christopher FREEMAN, a revolutionary technology
must satisfy the following criteria:
1. A new range of products accompanied by an improvement in the
technical characteristics of many products and processes
2. A reduction in costs of many products and services
3. Social and political acceptability
4. Pervasive effects through the economic system
BIOTECHNOLOGY has provided
incredible) powers over nature
humankind
with
substantial
(indeed
For a long time it has been assumed that EVOLUTION occurs through the
MUTATION OF GENES, which in turn generates the VARIETY, which, together
with the PROCESS OF SELECTION drives the EVOLUTIONARY PROCESSES.
BIOTECHNOLOGY, by providing the means to instantly COMBINE the
GENETIC MATERIAL of different organisms, has given humankind the awesome
POWER TO OVERRIDE NATURAL EVOLUTION, thereby achieving an
unexpected degree of control.
Examplary BIOTECHNOLOGIES to be discussed
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Fermentation and fermenters
Enzymes technology
In vitro techniques in plant breeding
Protein engineering
Bioprocessing
The genetics and politics of frost control
THE BIOTECHNOLOGY REVOLUTION
BIOTECHNOLOGY may be defined as:
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the use of biological organisms for commercial applications, or,
the study of commercial exploitation of biological materials, living
organisms and their activities .
BIOTECHNOLOGY is as old as human civilization, because;
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brewing of beer
fermentation of wine
production of yogurt and cheese
are all based on the use of biological organisms
During recent decades BIOTECHNOLOGY has received significant boost
from a number of powerful new techniques known collectively as GENETIC
ENGINEERING
GENETIC
ENGINEERING
techniques
allow
biotechnologists
to
CONTROLLABLY ALTER THE GENETIC STRUCTURE OF ORGANISMS by
adding or removing genes that allow the organism to perform new functions
GENE THERAPY
Genetic diseases are usually due to a faulty DNA which cannot produce
certain proteins in the body.
Until very recently, the only thing that physicians could do when faced with a
genetic disease was to treat the symptoms.
For example for diabetes treatment included
modification of the diet
injection of insulin
Such treatments did nor cure the disease but provided temporary solutions.
GENE THERAPY is defined as a procedure for REPLACING A DEFECTIVE
GENE
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defective gene is identified and isolated
it is repaired by genetic engineering
repaired genes are reproduced in vitro
new genes are returned to the patient
Gene therapy was first used successfully in the treatment of SCID.
(1) White blood cells were removed from the patient. (2) Normal
copies of the defective gene were inserted into the blood cells. (3)
The cells were placed in a culture (a medium of nutrients) to verify
that the DNA would replicate and proteins would form in the cell. (4)
The genetically modified cells were returned to the patient’s
bloodstream. Because white blood cells have a relatively short
lifespan, patients must undergo treatment regularly to maintain a
constant supply of normal genes.
HUMAN GENOME PROJECT (HGP)
The sum of all information contained in the DNA for any living thing or, the
sequence of all the bases in all the chromosomes, is known as that organism's
GENOME.
For humans this involves:
All 46 chromosomes and
All 3 billion base pairs or nucleotides
Each base (or nucleotide) on human genome carries 2 bits of information.
Total information content of human genome is:
3,000,000,000 x 2 = 6,000,000,000 bits
A letter in a textbook can be represented by 6 bits.
An average book page contains about 3,000 characters
3,000 characters / page x 6 bits / character = 18,000 bits / page
6,000,000,000 / 18,000 = 333,333 pages
This is approximately how much information is contained in every cell of a
human being.
Two important goals of the Human Genome Project are DNA
mapping and DNA sequencing. A genetic map shows the location
and sequence of genes along a chromosome. It can be used to
identify the genes for a specific trait. Scientists working on the
Human Genome Project are creating physical maps that describe
the chemical characteristics of the DNA molecule at any given
point. The physical maps will then be used for DNA sequencing,
which will determine the exact sequence of base pairs along a
DNA molecule.
The Goal of HUMAN GENOME PROJECT (HGP)
Complete understanding of the role and origins of genomic components with
the prospect of being able to disentangle the complex causes of human genetic
diseases.
In short the idea is to prepare a MAP of HUMAN GENOME. (MAPS are
linear representations that describe the organization of a set of landmarks
using a defined system of measurements based on coordinates)
This is a race against time with worldwide support and participation by
governments and industrial research groups.
Suggested reading:
The Human Blueprint
The Race to Unlock the Secrets of Our Genetic Script
Robert Shapiro
St Martins Press, 1991
Human DNA contains about 100,000 genes divided among 23 pairs of
chromosomes. First step of this enormous project is finding the location of
every gene on every chromosome
GENE is a unit of biological inheritance, or a section of a long molecule of DNA.
One gene carries the information needed to assemble one protein.
US Congress appropriated $3 Billion for HGP research for 15 and a National
Center for Human Genome Research NIH was established.
In 1990 HUGO (Human Genome Organization) carried HGP to the innational
platform, with financial support from Howard Hughes Medical Institute (USA)
and Wellcome Trust (UK). They set up offices in Bethesda (MD) and London (UK)
The role of HUGO was to coordinate the efforts of all countries involved in
order to prevent redundancy
During all these developments, there were also many concerns regarding the
scientific, social, legal and ethical issues.
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Will the genetic data generated impinge
opportunities and rights of the individual?
upon
the
freedom,
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Was it better to shift the huge amounts of money spent on this
project to the others which were more urgent?
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Will the HGP divert resources from all other areas of biological
research, including the trained researchers?
All of these questions were well addressed. The result was to CONTINUEUE
the HGP
The new question that came up was not "WHAT IF?" but “HOW FAST?"
The goal of HUMAN GENOME PROJECT (HGP)
HGP began in 1986 with an editorial by Renatto Dulbecco in Science (Vol. 231,
pp. 1055-1056, year 1986), where he argued that in order to be able to
understand and combat cancer, identification of all the genes involved was
necessary
Developing the idea further, he called for a National effort, similar to the
"effort to conquer the space" pointing out that many important findings will be
made that will benefit biology, medicine, pharmacology etc.
Support came from Department of Energy (DOE) and National Institute of
Health (NIH)
US Congress approved the initial funding for the program. NIH and DOE
worked on setting up a research agenda and organization (1988-1990)
Genome I meeting convened in October 1989 in San Diego, CA, which brought
international researchers together
October 1, 1990 was designated as the official start of HGP.
THE ETHICS OF GENES
Scientists can now detect many characteristics of an individual, including the
presence of life-threatening diseases, before birth
Enventually all human beings and even fetuses may be tested for a variety of
incurable diseases
With this knowledge comes an ethical challenge that will face the humanity in
the coming decades
WHAT SHOULD WE DO WITH THE GENETIC
INFORMATION?
Should parents be informed of the fate of their future child?
Should the prospect of an incurable disease provide grounds for abortion?
To whom should the information about a grown up conveyed? Family?
Employer? Insurance company?
Taking these issues a step further, it may soon be possible to alter an
individual's DNA in utero, during pregnancy. Where should the science stop?
Such genetic manipulation will allow:
Curing some genetic diseases
Improving IQ
Improving athletic ability
Changing height or eye color