That Covid-19 has Ghana WhatsApp Number List our lives is an open door that I will not push through. On the other hand, we must be aware that this adaptation will have to last well beyond confinement (see HERE a previous article on the subject). But these preventive measures and the strategies to be adopted are often poorly understood, and indeed sometimes poorly applied. I remembered on this occasion my (distant) studies in biology (agricultural engineer and thesis in biology). Without posing myself as an expert (there are already far too many kinds, see HERE the caustic speech of Senator Malhuret), I suggest you share some notions

on viruses, making it possible to better understand (and therefore better apply) these measures. Living or not living the virus? At the risk of surprising you, this question which seems elementary is still debated today. While no one disputes that viruses are part of the “living world”, their particularity is that they cannot “grow and multiply”, that is to say “live” in the sense in which we commonly understand it, without the invasion. and the hijacking of the metabolism of other living cells for their benefit. We then speak of an “obligatory intracellular parasite”: it is obligatory for it to enter a living cell in order to develop. But what exactly is a

Living Or Not Living The Virus

virus? The two diagrams opposite represent the same virus, parasite of a bacterium. For the record, it is phage T4, a virus from a bacteria common in our intestines and famous for having been one of the first objects of study in cell biology: Escherichia coli . Opposite two representations of this virus, phage T4. I am particularly proud of the drawing on the left, which is a scan of my Maths sup Bio class notes from… 1992 (and I spare you the sneers, at the back of the class). The one on the right is from a Wikipedia article . Good too, but more impersonal, let’s say. Our virus consists of a “capsid” (= kind of capsule, but more scientific fo


r serious) surrounding a strand of genetic code, DNA in this case, all mounted on a “landing gear Which looks like the Apollo capsule. And in fact, the resemblance is not only fortuitous since the only function of the whole is to “land” on the surface of a host cell (our Escherichia coli of earlier), to plant there his “needle” (hollow tube) and inject his DNA into it using his “syringe”, the contractile sheath. “A small step for T4 DNA, a big step for the virus”: from the moment the DNA strand has infected its host cell, it will gradually divert its resources so that the cell can no longer manufacture new proteins and cellsEscherichia coli , but rather virus

The Virus Transforms Each Infected

proteins, new capsids, new hollow tubes, new DNA strands, and ultimately new viruses ready to infect other cells. All of this is exponential, each infection releasing millions of new viruses, which themselves… etc. What good will you say to me? Infect, multiply, then re-infect … Not exciting the cycle of the virus. But beyond the “meaning of life”, slippery ground on which I will not venture, let us recognize that the mechanism is crowned with success, unfortunately allowing a very small thing of this kind, barely alive, to stop in their unbridled momentum the expansion of our multi-millennial human civilizations … The virus

transforms each infected cell, each host into a “virus-making factory” If we come back to our famous Covid-19, it has a significantly different shape but an identical mechanism: a strand of genetic code surrounded by a capsid and a protein envelope, with not a syringe but proteins capable of “Attach” to human cell receptors (lung cells or mucous membranes of the eyes and the ENT sphere, or even other organs afterwards). In this way, it can infect this first cell, multiply there, infect other cells … A phenomenal multiplication of the virus in the body (responsible for the famous “viral load” which we hear about in the news), with two direct effects: the progressive weakening of the host (we poor humans in this case), via infected cells and organs.

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