Molecular biology has shown that even the simplest of all living systems on the earth today, bacterial cells, are exceedingly complex objects. Although the tiniest bacterial cells are incredibly small, weighing less than 10-12 gms, each is in effect a veritable micro-miniaturized factory containing thousands of exquisitely designed pieces of intricate molecular machinery, made up altogether of one hundred thousand million atoms, far more complicated than any machine built by man and absolutely without parallel in the nonliving world.
YourGenome - From DNA to Protein
We all know that elephants only give birth to little elephants, giraffes to giraffes, dogs to dogs and so on for every type of living creature. But why is this so? The answer lies in a molecule called deoxyribonucleic acid (DNA), which contains the biological instructions that make each species unique. DNA, along with the instructions it contains, is passed from adult organisms to their offspring during reproduction.
The amount of information in human DNA is roughly equivalent to 12 sets of The Encyclopedia Britannica, an amazing 384 volumes worth of detailed information that would fill 48 feet of library shelves! But the size of a DNA molecule is only two millionths of a millimeter thick. In order for there to be anything resembling a language it must meet the following criteria; an alphabet or coding system, correct spelling, grammar (a proper arrangement of the words), meaning (semantics) and an intended purpose. It has been discovered that DNA meets all of these requirements and in fact, it has all of the same properties as any computer code or language does.
Protein biosynthesis refers to the process whereby biological cells generate new proteins... Translation, the assembly of proteins by ribosomes, is an essential part of the biosynthetic pathway, along with generation of messenger RNA (mRNA), aminoacylation of transfer RNA (tRNA), co-translational transport, and post-translational modification. Protein biosynthesis is strictly regulated at multiple steps, and error-checking mechanisms are in place.
The events going on in our cells can be compared to an orchestra playing a symphony. There are many different parts being played by a wide range of instruments.
Microbiotic - DNA transcription and translation
Transcription is the first step of gene expression, in which a particular segment of DNA is copied into RNA by the enzyme RNA polymerase. Both RNA and DNA are nucleic acids, which use base pairs of nucleotides as a complementary language that can be converted back and forth from DNA to RNA by the action of the correct enzymes.
Alternative splicing is a regulated process during gene expression that results in a single gene coding for multiple proteins. ... the proteins translated from alternatively spliced mRNAs will contain differences in their amino acid sequence and, often, in their biological functions.
Alternative splicing of precursor mRNA is an essential mechanism to increase the complexity of gene expression, and it plays an important role in cellular differentiation and organism development. Regulation of alternative splicing is a complicated process in which numerous interacting components are at work.
We now know that so-called "epigenetic changes" explain many hallmark features of malignant disease: these genes are deregulated not at the DNA level, but at the complexly packaged chromatin level, which ultimately results in cell dysfunction.
Epigenetic changes can boost or interfere with the transcription of a specific genes. The most common way in which interference happens is that DNA or the protein it's wrapped around gets labeled with small chemical tags. The set of all of the chemical tags that are attached to the genome of a given cell is called the epigenome.
For decades, we have thought of our offspring as blank slates. Now, epigeneticists are asking whether in fact our environment, from smoking and diet to pollution and war, can leave "epigenetic marks" on our DNA that could get passed on to subsequent generations. They call the phenomenon epigenetic inheritance.
Membranes organize proteins and other molecules enabling the cell to run much more efficiently than if everything were floating freely. Mitochondrial membranes, for example, keep protein assembly lines together for efficient energy production. \And the lysosome safely holds enzymes that would destroy essential proteins if released into the cytoplasm. Membrane-enclosed vesicles form packages for cargo so that they may quickly and efficiently reach their destinations. In this way, membranes divide the cell into specialized compartments, each carrying out a specific function inside the cell.
The lateral mobility of cell membranes plays an important role in cell signaling, governing the rate at which embedded proteins can interact with other biomolecules. The past two decades have seen a dramatic transformation in understanding of this environment, as the mechanisms and potential implications of nanoscale structure of these systems has become accessible to theoretical and experimental investigation.
It has long been known that cells release chemical signals in response to outside conditions, triggering reactions inside the cell. But it turns out that such communication is a two-way street: New research shows that cells' signaling mechanisms can tell whether their signals are being received, and then adjust the volume of their messages as needed.
By chance or by design?
No matter how many "bits" of possible combinations it has, there is no reason to call it "information" if it doesn't at least have the potential of producing something useful. What kind of information produces function? In computer science, we call it a "program." Another name for computer software is an "algorithm." No man-made program comes close to the technical brilliance of even Mycoplasmal genetic algorithms. Mycoplasmas are the simplest known organism with the smallest known genome, to date. How was its genome and other living organisms' genomes programmed?