The living

The mystery of nothingness

The story of the evolution towards the living, starts from nothing, there is 13.7 billion years before, the time and space do not exist.
The microscopic and the macroscopic world are gathered in the evolution of the Universe as the infinitely small, infinitely generated large, the observable universe, sprang from nothing.
The universe was so small that pregnancy was in the palm of the hand, it is from there that have formed the first stars and galaxies and planets...
Initially, an energy mysteriously blurred, creating billions of billions of billions of virtual particles and antiparticles, which will leave the opaque world of shadows, to emerge in the real world transparent.

Quarks A quark (pronounced /ˈkwɔrk/ or /ˈkwɑrk/) is an elementary particle and a fundamental constituent of matter. Quarks combine to form composite particles called hadrons, the most stable of which are protons and neutrons, the components of atomic nuclei. Due to a phenomenon known as color confinement, quarks are never found in isolation; they can only be found within hadrons. For this reason, much of what is known about quarks has been drawn from observations of the hadrons themselves. , electrons The electron is a subatomic particle carrying a negative electric charge. It has no known components or substructure. Therefore, the electron is generally believed to be an elementary particle. An electron has a mass that is approximately 1/1836 that of the proton. , neutrino A neutrino, meaning "small neutral one" is an elementary particle that usually travels close to the speed of light, is electrically neutral, and is able to pass through ordinary matter almost unaffected. This makes neutrinos extremely difficult to detect. Neutrinos have a very small, but nonzero rest mass. They are denoted by the Greek letter ν (nu).  and their antiparticles in the free state, will emerge from a mysterious void. Particles and their antiparticles will produce light, lots of light, is the birth of the radiative era, the observable universe.
The energy of the strong nuclear force creates matter, involving quarks of three, is the time of hadrons which appear protons and neutrons.
At that time, the quarks lose their freedom.

The boundary between the inert and the living

Life is a chemical process in which living organisms are derived.
Matter of life on Earth and this is certainly elsewhere in the universe for billions of years. In meteorites organic oldest, the scientists found the basics of life that have fueled the matter early Earth, there is a little over 4 billion years.
Life began protecting themselves inside cell membranes, cellular life on Earth. A mixture of organic compounds as simple as that contained in a carbonaceous meteorite, can form cell membranes and this contributed to the formation of first cells on the early Earth.
Scientists imagine the early stages of creating the first living cells, but very old organic molecules and cell membranes do not reveal almost nothing of the mysterious passage of matter to life.
What is certain is that we are made of matter but at the same time, we will distinguish. What sets us apart from the matter is that we are "alive" and not "inert".
We say that a organism is alive if it can feed, grow and reproduce to pass the time.

Since life is chemical and has its origin in dead matter, why not find one not the precise boundary between living and inanimate?
A virus for example, is an assemblage of atoms inert, it is inanimate and yet it acts like a living organism, reproducing and mutant, when it infects a cell.
The lifeless and the living is strangely similar in the crystal, which grows and multiplies while being inert.
Archaea or archaebacteria or archaea, cells are 10 times smaller than bacteria and sequence of their DNA shows they are closer to the first living organism than bacteria. They are found on Earth that live in extreme conditions, which shows their phenomenal capacity to adapt. That's why researchers are trying to remove the maximum amount of information stored, by modifying their DNA, to keep a living organism "minimal" and reach the border between inanimate and living. 

Image: Methanogens microorganisms are in the branch of Archaea and producing methane gas which has played a major role in evolution.

Life on Earth

Life is a mysterious and universal tendency of matter to associate, to organize, to become more complex. The living is characterized in that it draws energy in the external environment, it uses this energy, waste and rejects expanding its organization. At the species level, life on Earth, is getting more and more complex faster, for 4.5 billion years. It seems that life, as it is tenacious, is nothing else than a trivial process, a particular form of matter, which we will certainly discover the secret. However we find that life evolves in time by taking a path defined by an infinite number of parameters, which makes it unpredictable and indefinable.
But there is a biological definition of life: "an organism is alive when said exchange of matter and energy with its environment by maintaining its autonomy when it replicates and evolves by natural selection. "
All living organisms ensure their stability by responding to changes in their environment. Life has a faculty of adaptation and learning. This is life?
But we also see by observing the galaxies, stars and planets, that matter is able to self-organize without being alive.

However, a good definition of life must take into account this concept, ie, the ability of the material to gradually climb the ladder of complexity.
The tenacity of life is it not proof that it is present everywhere in the universe, patiently waiting for favorable conditions to continue its path to complexity? It is difficult to believe that life exists on Earth, wherever there is liquid water, there is a possibility of life, even under the icy crust of planets or satellites of planets.
Life thrives in places where even the sun's energy does not penetrate, we see into the depths of our planet.

NB: According to NASA, is alive any system defined spatially by a semipermeable membrane of its own manufacture and capable of self-sustaining, and reproduce by making its own components, from power and / or from outside elements.

Image: Note in the photo enlarged, the frail membrane of the Earth's atmosphere that protects life. It seems that Earth, like the cell, protected life inside a cell membrane.

The living and Information

The definition of life is extremely difficult to design and scale of the issue does not respond simply because the issue concerns both the philosophical as the chemistry of life.
In addition we find that life evolves in time by taking a path defined by an infinite number of parameters, which makes it unpredictable and indefinable.
But the components present in the original soup from time to time, establish electromagnetic links. And when certain components are combined, they channel the information to make a copy for themselves, that is where the miracle occurs because, in a system of chemicals that is not alive, it does happening.
The chemical functions of these particular components, assembled by chance, are part of a manufacturing plan that allows the system to repeat.

This system has operational information stored, and it is from this point on, it can be considered alive.
This living system has the particularity to recreate the infinite, from the constituents of the medium, is said to possess the property of autopoiesis.
The term comes from the Greek auto (self) and poiesis (creation). This term defines the property of a system to produce itself.
In 1944 Avery, MacLeod and McCarthy identify DNA as carrier of genetic information.
Life is primarily a chemical process that tends toward complexity, but it evolves into more complex and less they will be found alike in the universe.
Life tends to scarcity!

?
consciences
agencies
cells
biomolecules or proteins
simple molecules
atoms
nucleons
quarks, electrons
chaos
?

Image: The pyramid of complexity goes into depletion, the more you go the less complexity and can be found in the universe.

The cell

The cell is the basic unit of living systems is the unity of life.
In 1838, Matthias Schleiden hypothesized that all plants are composed of cells and in 1839, Theodor Schwann extended the hypothesis to all animal tissues.
Schwann Schleinden and thus pose the argument that cells are the elementary particles of life.
The cell, this little room, provides protection and creates an environment that allows physicochemical composition to the confined space of exchange with the outside. Cells, but not necessarily identical to the same origin, came together to form a tissue level of organization and functional fabrics come together to form organs.
In short, life is organized through the cells, tissues, organs and systems for manufacturing organizations as sophisticated as consciousness.
The DNA, genetic information and heredity, produces occasional errors, most mistakes are bad, but sometimes these mutation, depending on the environment, produce beneficial effects, which allow the system to continue its evolution...
Deoxyribonucleic acid or DNA is a molecule present in all living cells. This wonderful molecule contains all the information necessary to operate a system.
It will allow the transmission of information, fully or substantially during reproduction. This genetic information is the genome of living beings.
DNA contains the manufacturing plan, it simply consists of 4 components that allow replication: JMA and T (adenine, guanine, cytosine and thymine.

The DNA molecule is a double-strand which allows the duplication into two identical daughter DNA molecules. This ensures the transmission of genetic information during reproduction is heredity. Each molecule daughter inherits one strand of the original DNA molecule.
The other strand is synthesized, the complementary components are placed by AT and GC, so as to reconstitute the same strand missing.
The 2 new molecules ADN are identical to the original molecule. The two strands with complementary sequences are linked by weak bonds, which allows separation and reassembly of the strands.
In 1958, the Meselson-Stahl experiment has validated this model. Living organisms contain molecules such as carbohydrates, lipids, nucleic acids and proteins, but all based on carbon.
Life forms could in theory be based on silicon, but it does not show the amazing variety of shapes and properties of carbon.

Image: In the strand, the stability of genetic information is carried by strong bonds but the DNA can change. Spontaneous mutations are probably due to matching errors during replication or facilitated by the environment (radiation, ultraviolet,...).