Revelations by Science
The most intrigue feature about life that it is a virtue though it’s not materialistic, but it is a combined output of assemblage of large molecules and a vast network of reactions we call Metabolism. Now we know that all living creatures are made of cells which are considered as fluid filled compartments surrounded by membrane.
Our understanding towards life till now based on two important questions; first that how the cells are originated as an independent system of life? And second, how these cells interact with each other to make such intricate organs and organisms?
Researches and speculations lead us to an understanding that all the organisms and the cells that constitute them are descended from a common ancestor cell. This happened in a vast gap of time and via processes like evolution and natural selection. Out little understanding about the universe and origin of the earth, make it clear that in its first billion years earth was violent with volcanic eruptions lightening and torrential rains. The temperature then was high, and Earth was receiving all the radiation from the sun. These conditions allowed the interaction of atoms to form inorganic molecules which further progressed to develop simple organic molecule. The formation of molecules like amino acids and nucleotides, considered as marker events. Amino acids and nucleotides get polymerized to form polypeptides and proteins and polynucleotides Ribonucleic acid and Deoxyribonucleic acid. While the protein forming amino acid is about 20 different types and 4 basic nucleotides are involved in polynucleotide synthesis, is universal to all life forms. Further the qualities like catalysis, autocatalysis and replication allowed development of new molecules and self-renewal to polypeptides and polynucleotides. A network of interconnected spontaneous reactions, allows the primordial structures to attain stability and further to produce similar structure. The key of which lies in the nucleic acids. Nucleic acids self-replicate to produce their copies and transfer them to the new structure. These primitive structures, surrounded by membrane considered as first cell.
Information transfer system of current cells is another inclusive feature that developed, which is considered as central dogma of life. Nucleic acids perform transcription to form complimentary RNA molecules, the translation of which allows the synthesis of polypeptides and proteins.
With the passage of time cells evolved as a fundamental units of life capable of performing all necessities of survival and reproduction. Every new cell receives genetic material from the parent cell, which contains information in form of sequence of nucleotides studies in form of codes. These codes are triplet in nature. This coded information gets transcribed in to RNA molecules, where each codon represents a specific amino acid. Modern day cells possess a translation machinery to read these codons and add amino acids one after the other to form a peptide or polypeptide.
It is evident that codons are universal in nature that is form simplest organisms to most complex ones have same codons coding the same amino acids. Ribosome, a special organelle, is responsible for translation. Ribosomes are small circular structures, made of RNA and Proteins. They slide over the template RNA read codons and allows the formation of peptides.
With time primitive cell evolved as a steady state system. It became possible with natural selection. In primordial soup when newly formed organic molecules were trying to get stabilised their reactions and formation cycles, only the most efficient ones survived.
This became possible with the development of specialised covering membranes. Modern day cells have covering membranes made of amphipathic molecules like lipids. Amphipathic molecules have both hydrophobic and hydrophilic segments, this allows them to form bilayers in aqueous solutions. Plasma membrane is one such type of membranes which get modified with time. Development of membranes permitted accumulation and aggregation of reactions systems to establish their own work proximities.
The other feature that is necessary for survival is regulation. Cells are like small factories, with numerous small equipment operating all together and spontaneously. Cell regulate and control all the processes under the unified center of genetic material.
Interestingly science looks sophisticated with unimaginable depths of researches. This very little understanding that took years of research and the lives of thousands of scientists dissolved to give this information a viable shape. But that’s the beauty of life itself as small and as large, as strong as delicate, as sharp as wide, its everything or nothing in moments. Though enormous efforts have been made, still Control over life is by far from approach of mankind. The miraculous nature of origin of life dominated the history and its evident that mankind evolved to believe in supernatural powers that tend to control life.
(to be continued….)