What is energy?
Look around you. Is anything moving?
Can you hear, see or feel anything? Sure... this is because something is making
something happen, and most probably, there is some power at work. This power or
ability to make things happen is what we can call energy. It makes things happen. It
makes change possible.
Look at the sketch below to see an example of things working, moving, or
happening... with energy.
Energy in action
Energy moves cars along the roads and makes aeroplanes fly. It plays our
music on the radio, heats our rooms and lights our homes. Energy is needed for our
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bodies, together with plants to grow and move about.
Scientists define ENERGY as the ability to do work.
Energy can be neither created nor destroyed.
Energy can be (is) stored or transferred from place to place, or object to object
in different ways. There are various kinds of energy.
Let's start by looking at kinetic energy.
Kinetic Energy
All moving things have kinetic energy. It is energy possessed by an object due
to its motion or movement. These include very large things, like planets, and very
small ones, like atoms. The heavier a thing is, and the faster it moves, the more
kinetic energy it has.
Now let's see this illustration below.
There is a small and large ball resting on a table.
Kinetic energy example
Let us say both balls will fall into the bucket of water.
What is going to happen?
Motion energy example
You will notice that the smaller ball makes a little splash as it falls into the
bucket. The heavier ball makes a very big splash. Why?
Note the following:
1. Both balls had potential energy as they rested on the table.
2. By resting up on a high table, they also had gravitational energy.
3. By moving and falling off the table (movement), potential and gravitational
energy changed to Kinetic Energy. Can you guess which of the balls had more kinetic
energy? (The big and heavier ball).
Mechanical Energy
Mechanical energy is often confused with Kinetic and Potential Energy. We
will try to make it very easy to understand and know the difference. Before that, we
need to understand the word ‘Work’.
‘Work’ is done when a force acts on an object to cause it to move, change
shape, displace, or do something physical. For, example, if I push a door open for my
pet dog to walk in, work is done on the door (by causing it to open). But what kind of
force caused the door to open? Here is where Mechanical Energy comes in.
Mechanical energy is the sum of kinetic and potential energy in an object that
is used to do work. In other words, it is energy in an object due to its motion or
position, or both. In the 'open door' example above, I possess potential chemical
energy (energy stored in me), and by lifting my hands to push the door, my action
also had kinetic energy (energy in the motion of my hands). By pushing the door, my
potential and kinetic energy was transferred into mechanical energy, which caused
work to be done (door opened). Here, the door gained mechanical energy, which
caused the door to be displaced temporarily. Note that for work to be done, an object
has to supply a force for another object to be displaced.
Here is another example of a boy with an iron hammer and nail.
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The iron hammer on its own has no kinetic energy, but it has some potential
energy (because of its weight).
To drive a nail into the piece of wood (which is work), he has to lift the iron
hammer up, (this increases its potential energy because if its high position).
And force it to move at great speed downwards (now has kinetic energy) to hit
the nail.
The sum of the potential and kinetic energy that the hammer acquired to drive
in the nail is called the Mechanical energy, which resulted in the work done.
Sound Waves
Sound energy is usually measured by its pressure and intensity, in special units
called pascals and decibels. Sometimes, loud noise can cause pain to people. This is
called the threshold of pain. This threshold is different from person to person. For
example, teens can handle a lot higher sound pressure than elderly people, or people
who work in factories tend to have a higher threshold pressure because they get used
to loud noise in the factories.
Heat (Thermal energy)
Matter is made up of particles or molecules. These molecules move (or vibrate)
constantly. A rise in the temperature of matter makes the particles vibrate faster.
Thermal energy is what we call energy that comes from the temperature of matter.
The hotter the substance, the more its molecules vibrate, and therefore the higher its
thermal energy.
For example, a cup of hot tea has thermal energy in the form of kinetic energy
from its vibrating particles. When you pour some milk into your hot tea, some of this
energy is transferred from the hot tea to the particles in the cold milk. What happens
next? The cup of tea is cooler because it lost thermal energy to the milk. The amount
of thermal energy in an object is measured in Joules.
Temperature
The temperature of an object is to do with how hot or cold it is, measured in
degrees Celsius (°C). Temperature can also be measured in a Fahrenheit scale, named
after the German physicist called Daniel Gabriel Fahrenheit (1686 – 1736). It is
denoted by the symbol 'F'. In Fahrenheit scale, water freezes at 32 °F, and boils at
212 °F. In Celsius scale, water freezes at 0°C and boil at 100°C.
A thermometer is an instrument used to measure the temperature of an object.
Let's look at this example to see how thermal energy and temperature are
related:
A swimming pool at 40°C is at a lower temperature than a cup of tea at 90°C.
However, the swimming pool contains a lot more water. Therefore, the pool has more
thermal energy than the cup of tea even though the tea is hotter than the water in the
pool.
Let us see this example below:
If we want to boil the water in these two beakers, we must increase their
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temperatures to 100°C. You will notice that will take longer to boil the water in the
large beaker than the water in the small beaker. This is because the large beaker
contains more water and needs more heat energy to reach 100°C.
Polymers are studied in the fields of biophysics and macromolecular science,
and polymer science (which includes polymer chemistry and polymer physics).
Historically, products arising from the linkage of repeating units by covalent
chemical bonds have been the primary focus of polymer science; emerging important
areas of the science now focus on non-covalent links. Polyisoprene of latex rubber
and the polystyrene of Styrofoam are examples of polymeric natural/biological and
synthetic polymers, respectively. In biological contexts, essentially all biological
macromolecules—i.e., proteins (polyamides), nucleic acids (polynucleotides), and
polysaccharides—are purely polymeric, or are composed in large part of polymeric
components—e.g., isoprenylated/lipid-modified glycoproteins, where small lipidic
molecules and oligosaccharide modifications occur on the polyamide backbone of the
protein.
A polymer is a large molecule, or macromolecule, composed of many repeated
subunits. Because of their broad range of properties,[4] both synthetic and natural
polymers play an essential and ubiquitous role in everyday life.[5] Polymers range
from familiar synthetic plastics such as polystyrene to natural biopolymers such as
DNA and proteins that are fundamental to biological structure and function.
Polymers, both natural and synthetic, are created via polymerization of many small
molecules, known as monomers. Their consequently large molecular mass relative to
small molecule compounds produces unique physical properties, including toughness,
viscoelasticity, and a tendency to form glasses and semi crystalline structures rather
than crystals.
A nano-world of technologies
There are high hopes that research in nanotechnology will translate into many
products and devices that will help people. The technology will affect a wide range of
fields, including transportation, sports, electronics, and medicine. Some of the current
and future possibilities of nanotechnology includes:
- Medicine: Researchers are working to develop nanorobots to help diagnose
and treat health problems. Medical nano robots, also called nanobots, could someday
be injected into a person bloodstream. In theory, the nanobots would find and destroy
harmful substances, deliver medicines, and repair damage.
- Sports: Nanotechnology has been incorporated in outdoor fabrics to add
insulation from the cold without adding bulk. In sports equipment, nanotech metals in
golf clubs make the clubs stronger yet lighter, allowing for greater speed. Tennis balls
coated with nanoparticles protect the ball from air, allowing it to bounce far longer
than the typical tennis ball.
- Materials Science: Nanotechnology has led to coatings that make fabric stain
proof and paper water resistant. A car bumper developed with nanotechnology is
lighter yet a lot harder to dent than conventional bumpers. And nanoparticles added
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to surfaces and paints could someday make them resistant to bacteria or prevent dirt
from sticking.
Electronics: The field of nano-electronics is working on miniaturizing and
increasing the power of computer parts. If researchers could build wires or computer
processing chips out of molecules, it could dramatically shrink the size of many
electronics.
Heal The World
Biotech is helping to heal the world by harnessing nature's own toolbox and
using our own genetic makeup to heal and guide lines of research by:
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Reducing rates of infectious disease;
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Saving millions of children's lives;
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Changing the odds of serious, life-threatening conditions affecting millions
around the world;
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Tailoring treatments to individuals to minimize health risks and side effects;
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Creating more precise tools for disease detection; and
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Combating serious illnesses and everyday threats confronting the developing
world.
Fuel The World
Biotech uses biological processes such as fermentation and harnesses
biocatalysts such as enzymes, yeast, and other microbes to become microscopic
manufacturing plants. Biotech is helping to fuel the world by:
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Streamlining the steps in chemical manufacturing processes by 80% or
more;
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Lowering the temperature for cleaning clothes and potentially saving $4.1
billion annually;
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Improving manufacturing process efficiency to save 50% or more on
operating costs;
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Reducing use of and reliance on petrochemicals;
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Using biofuels to cut greenhouse gas emissions by 52% or more;
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Decreasing water usage and waste generation; and
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Tapping into the full potential of traditional biomass waste products.
Feed The World
Biotech improves crop insect resistance, enhances crop herbicide tolerance and
facilitates the use of more environmentally sustainable farming practices. Biotechis
helping to feed the world by:
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Generating higher crop yields with fewer inputs;
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Lowering volumes of agricultural chemicals required by crops-limiting the
run-off of these products into the environment;
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Using biotech crops that need fewer applications of pesticides and that allow
farmers to reduce tilling farmland;
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Developing crops with enhanced nutrition profiles that solve vitamin and
nutrient deficiencies;
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Producing foods free of allergens and toxins such as mycotoxin; and
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Improving food and crop oil content to help improve cardiovascular health.
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Have you ever heard the expression “you can’t tell the players without a
program” and found it to be true? Sometimes you need background information, a list
of the players, their titles or functions, definitions, explanations of interactions and
rules to be able to understand a sporting event, a theatrical play or a game. The same
is true for understanding the subtle but important differences among the various
components that make up an ecosystem.
Terms suchas individual, population, species, community andecosystem all
represent distinct ecological levels and are not synonymous, interchangeable terms.
Here is your brief guide or program to understanding these ecological players.
You are an individual, your pet cat is an individual, a moose in Canada is an
individual, a coconut palm tree on an island in the Indian Ocean is an individual, a
gray whale cruising in the Pacific Ocean is an individual, and a tapeworm living in
the gut of a cow is an individual, as is the cow itself. An individual is one organism
and is also one type of organism (e.g., human, cat, moose, palm tree, gray whale,
bacterium, or cow in our example). The type of organism is referred to as the species.
There are many different definitions of the word species, but for now we’ll leave it
simply that it is a unique type of organism. As a grammatical aside, note that the
word “species” always ends in an “s”. Even if you are referring to just one type of
organism, one species, it is a species; there is no such thing as specie. That’s just one
of those grammatical facts of life.
So what is a gene?
Genes are instruction manuals in our body. They are molecules in our body that
explain the information hidden in our DNA, and supervises our bodies to grow in line
with that information.
It is believed that each cell in our body contains over 25,000 genes, all working
together. These genes carry specific biological codes or information that determine
what we inherit from our parents.
Genes are also a small section of Deoxyribonucleic Acid (DNA), a chemical
that has a genetic code for making proteins for living cells. Proteins are the building
blocks for living things. Almost everything in our body, bones, blood and muscles are
all made up of proteins, and it is the job of the genes to supervise protein production.
Genes are not things we see with our bare eyes. They can only be seen with
powerful microscopes, and they are thread-like in nature, found in our chromosomes.
Altered or mutated genes:
Sometimes our genes do not work well. Sometimes we inherit genes that have
some problems. Such genes (also called mutated or altered genes) do not perform
their functions well, and cause defects in our organs. Some inherited diseases like
cancer and sickle cell have been linked to such mutated or bad genes. There is still a
lot of research going on in the study of genes to learn more about them.
What is a chromosomes?
A chromosome is just a compact store of DNA. A chromosome is simply a lot
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of DNA strands folded and compacted together. This compacting is done in a special
way. The Chemical bases in the DNA are held in place by The Double Helix. The
Double Helix continues to wrap itself around proteins. They continue to wrap around
several protein molecules and into an even bigger compact set which we call
Chromosome.
Chromosomes are all contained in the nucleus of the cell. nucleus
The number of Chromosomes in a cell depends on what cell it is.
Chromosomes in a tiny goldfish may be a lot less than that of a human. In fact,
humans have 46 chromosomes in each of the cells of our organs. These are organized
into two sets of 23 chromosomes.
Each human gets 23 chromosomes from their mom, and 23 chromosomes from
their dad. This is why almost everyone has some traits they got from their parents.
By looking at the chromosomes in the cell, we can tell the gender of an unborn
baby. Males have XY chromosomes and females have XX chromosomes.
These are called Sex Chromosomes.
During sexual activity (mating), the male releases the sperm cell and the
female releases the ova (female cell). Remember we said previously that the human
body has 23 pairs of chromosomes? Yes, the 23rd chromosome is your sex
chromosomes. Boys carry XY chromosomes and girls carry XX cromosomes.sex
chromosomes During fertilization, each parent contributes a cell each. The female
always contributes and X cell (because that all she has, XX chromosome) The male
contributes either an X or a Y cell. The male has no control over this, as it is purely
random.
If the male releases and X chromosome, it adds to the X chromosome of the
female, it forms an XX— and the gender of the baby will be a girl. If the male
releases a Y chromosome and adds to the females X chromosome, it forms an XY
and the gender of the baby is a boy.
In recent years, it is possible to have IVF which means In vitro fertilization.
This is where the female and male cells are taken from the parents and fertilized in a
lab. In IVF, it is possible to choose which sex chromosomes to fertilize. This means
you can choose to have a boy or girl.
What is genetic variation?
Individuals in a population are not exactly the same.
Each individual has its unique set of traits, such as size, color, height, body
weight, skin colour and even the ability to find food.
Sometimes, offspring’s of the same parents still differ a lot among themselves.
You can find that among 3 sisters, one may be very tall, the other may have dark hair
and the third may have a rounded nose tip. Such differences in individuals from the
same parents are called variation.
Characteristics or traits that are inherited are determined by genetic
information. Some other traits like dialect or accent, scars, skin texture or even body
weight may be determined by some external or environmental factors.
These factors include
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genesbulletDiet
genesbulletClimate
genesbulletCulture
genesbulletLifestyle
genesbulletLanguage
genesbulletAccidents
Sometimes a person may not have inherited a trait, but some conditions have
modified the individual to exhibits specific traits. If a child with brown eyes acquires
a disease that affects his eyes and turns them yellow, that may be a diseased induced
variation.
In the same vain, a child my have the tendency to be tall, but diseases and poor
diet during his early years my cause him to have stunted growth.
Laser surgery is also growing in popularity and application. As its name
suggests, surgeons utilize a laser to perform various procedures, including during
laparoscopic procedures. For example, lasers currently are used to excise cancerous
tissue from the larynx, reshape the cornea of an eye to allow a patient to see better,
and even to resurface the skin of a patient's face by burning off old layers skin so that
new skin can grow. The growing popularity of lasers as surgical devices is due
mainly to their ability to precisely destroy unwanted or abnormal tissue without
bleeding.
Another well known example of advancing surgical techniques involves
combating cardiovascular disease. Because of lifestyle habits or genetic
predisposition, fatty acids (plaque) sometimes build up in arterial walls. As more
plaque builds up, less blood is able to flow through the artery to the heart. Ultimately,
the plaque buildup may completely block the artery, preventing any blood from
flowing through it. The result is cardiac arrest, which can be fatal. Surgeons have
developed a technique known as angioplasty to combat the onset of cardiovascular
disease. Using a technique similar to laparoscopy, a surgeon inserts a thin tube into
the patient, working it up the artery to where the blockage resides. At the end of the
tube is a small, balloon-like device that inflates, pressing the plaque against the
arterial walls so that blood flow through the artery can be increased.
Surgeons have also developed another, more popular, procedure for dealing
with coronary artery disease: the coronary bypass graft operation. By taking a portion
of an artery from elsewhere in the patient's body--usually the internal mammary
artery from inside the chest cavity--the new artery is grafted around the blockage of
the old artery to allow blood to flow around the blockage via the new arterial route.
Despite the fact that this procedure requires open-heart surgery.
Man's influence on nature. Man is not only a dweller in nature, he also
transforms it. From the very beginning of his existence, and with increasing intensity
human society has adapted environing nature and made all kinds of incursions into it.
An enormous amount of human labour has been spent on transforming nature.
Humanity converts nature's wealth into the means of the cultural, historical life of
society. Man has subdued and disciplined electricity and compelled it to serve the
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interests of society. Not only has man transferred various species of plants and
animals to different climatic conditions; he has also changed the shape and climate of
his habitation and transformed plants and animals. If we were to strip the
geographical environment of the properties created by the labour of many
generations, contemporary society would be unable to exist in such primeval
conditions.
Man and nature interact dialectically in such a way that, as society develops,
man tends to become less dependent on nature directly, while indirectly his
dependence grows. This is understandable. While he is getting to know more and
more about nature, and on this basis transforming it, man's power over nature
progressively increases, but in the same process, man comes into more and more
extensive and profound contact with nature, bringing into the sphere of his activity
growing quantities of matter, energy and information.
On the plane of the historical development of man-nature relations we may
define certain stages. The first is that of the complete dependence of man on nature.
Our distant ancestors floundered amid the immensity of natural formations and lived
in fear of nature's menacing and destructive forces. Very often they were unable to
obtain the merest necessities of subsistence. However, despite their imperfect tools,
they worked together stubbornly, collectively, and were able to attain results. This
process of struggle between man and the elements was contradictory and frequently
ended in tragedy. Nature also changed its face through interaction with man. Forests
were destroyed and the area of arable land increased. Nature with its elemental forces
was regarded as something hostile to man. The forest, for example, was something
wild and menacing and people tried to force it to retreat. This was all done in the
name of civilization, which meant the places where man had made his home, where
the earth was cultivated, where the forest had been cut down. But as time goes on the
interaction between man and nature is characterized by accelerated subjugation of
nature, the taming of its elemental forces . The subjugating power of the implements
of labour begins to approach that of natural forces. Mankind becomes increasingly
concerned with the question of where and how to obtain irreplaceable natural
resources for the needs of production. Science and man's practical transforming
activity have made humanity aware of the enormous geological role played by the
industrial transformation of earth.
At present the interaction between man and nature is determined by the fact
that in addition to the two factors of change in the biosphere that have been operating
for millions of years—the biogenetic and the a biogenetic—there has been added yet
another factor which is acquiring decisive significance—the techno genetic. As a
result, the previous dynamic balance between man and nature and between nature and
society as a whole has shown ominous signs of breaking down. The problem of the
so-called replaceable resources of the biosphere has become particularly acute. It is
getting more and more difficult to satisfy the needs of human beings and society even
for such a substance, for example, as fresh water. The problem of eliminating
industrial waste is also becoming increasingly complex. The threat of a global
ecological crisis hangs over humanity like the sword of Damocles. His keen
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awareness of this fact has led man to pose the question of switching from the
irresponsible destructive and polluting subjugation of nature to a reasonable
harmonious interaction in the "technology-man-biosphere" system. Whereas nature
once frightened us and made us tremble with her mysterious vastness and the
uncontrollable energy of its elemental forces, it now frightens us with its limitations
and a new-found fragility, the delicacy of its plastic mechanisms. We are faced quite
uncompromisingly with the problem of how to stop, or at least moderate, the
destructive effect of technology on nature. In socialist societies the problem is being
solved on a planned basis, but under capitalism spontaneous forces still operate that
despoils nature's riches.
Unforeseen paradoxes have arisen in the man-nature relationship. One of them
is the paradox of saturation. For millions of years the results of man's influence on
nature were relatively insignificant. The biosphere loyally served man as a source of
the means of subsistence and a reservoir for the products of his life activity. The
contradiction between these vital principles was eliminated by the fact that the
relatively modest scale of human productive activity allowed nature to assimilate the
waste from labour processes. But as time went on, the growing volume of waste and
its increasingly harmful properties destroyed this balance. The human feedback into
nature became increasingly disharmonised. Human activity at various times has
involved a good deal of irrational behaviour. Labour, which started as a specifically
human means of rational survival in the environment, now damages the biosphere on
an increasing scale and on the boomerang principle—affecting man himself, his
bodily and mental organisation. Under the influence of uncoordinated production
processes affecting the biosphere, the chemical properties of water, air, the soil, flora
and fauna have acquired a negative shift. Experts maintain that 60 per cent of the
pollution in the atmosphere, and the most toxic, comes from motor transport, 20 per
cent from power stations, and 20 per cent from other types of industry.
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