The SARS COV2 Story

The Virus:

The virus must propagate its line. That is the only purpose for which it has come to this earth. For this it must invade a human lung cell, inhabit it. By the time it completes its journey on this planet it would have been multiplied into a thousand daughter viruses. That is what viruses have been doing for billion years and still going strong while the large animals like the Dinosaurs and the mammoths have gone extinct.

The RNA viruses are smart travellers, especially the novel SARS COV2 that will run a pandemic on earth. On this important mission, the virus picks up a smart card, a spike protein that will exactly fit into the hi-fi lock of human lung cells. It packs only two equipments in its briefcase.

• A pair of scissors and
• A Copier specially made for the mission

Rest of the things it has to outsource from the human cell itself. She is sure all the raw materials for a thousand daughter cells will be plentily available at the destination.

The Human Lung Cell:

The lung cell of the Homo sapiens is a fortress. It houses the power supply for the three trillion cells of the whole human body. It harvests oxygen from the thin air, bottles it into a special cargo called Haemoglobin, packs them inside a sleek, round, red convertible called RBC then despatches them everywhere from Brain to foot. One human body owns 30 trillion such little red vehicles that criss-cross the 66,000 miles to deliver oxygen to the distant corners of body. It is said any corner of the body will shut off, if its oxygen supply is cut off for a mere 4 minutes.

The human lung cells are one of the three vital installations of the Sapiens. It filters 6 litre of raw air every minute 24 hours a day, 7 days a week for at least 60 years. It also inhales 1 million invaders belonging to 1000 different types. Not all of them are friendly. The vault of exchange called the alveoli are a virtual fortress. They are wrapped with a spotless, slippery, sleek coat made of a double layer of fat and protein. Protein gives it tensile strength and fat makes it extremely slippery. Even the Ghorpade, that sly lizard of Shivaji Raje would not be able to scale it.

But there is only one chink in the armour, its Achilles’ heel. It has one single entry for receiving its daily essentials. This entrance is guarded by their highest security lock. It has a quaint name: the ACE receptor.

In 2019, the security of that high security vault has been breeched and the assasin has accessed its high security password. She has a name: SARS COV2.

An Ideal traveller:

The RNA virus is an ideal traveller. It knows that this is its final journey for a target from which it won’t return. She travels extreme light and swift like an expert assassin, flies inside an human lung cell in the air, locates it target and inserts its spike in. The alveolus of human lung cell scans the password and allows the spike in. Soon the assassin is inside a dark airy seamless vault with its spike still struck behind in the key whole of the  ACE system. It has to sacrifice the spike. It has outlived its utility.

Control+X:

The virus picks up the first instrument from its briefcase. The Protease. It has the deadliest Control+X program of the universe. It can cleave any protein however tensile neatly. The assassin deftly slices the spike, release herself from the inner wall of slippery lipo-protein wall and swims on.

It takes a little exploration to home on to its target, The Ribosome. This is the manufacturing hub of the sapiens. It has banks of 3D printers that go on printing the 20,000 odd proteins a human will be needing for its daily chores. The virus looks happy. The unit is literally floating in the pool of all varieties of amino-acids. Amino acids are the building blocks of protein that sustains every structure of life. She had a list of specific amino acids in her mind that will be used to create the six proteins for her daughter cells (Pic.). She had the blue print, the code. In one swift action, the assassin takes over the ribosome. But there is a problem.

Central dogma of molecular Biology:

In the animal world on this planet DNA makes RNA. RNA makes Protein. Proteins run the life. Accordingly the copier that human cell has is a Polymerase that can read the code from a DNA, not RNA. This virus comes from the RNA world where DNAs do not matter. The assassin reaches for the only other instrument that she has been carrying, a special copier: a Polymerase called RNA dependent RNA Polymerase (RDRP). 

Control+C:

She deftly sets up this special program that transcribes a copy of all the codes from the RNA codes she is carrying. Under the searching gaze of the assassin, the human ribosome stops printing insulin and other human proteins. It now prints out million copies of the viral protein.

The whole operation takes half an hour.

Assembly of a daughter virus:

But there are plenty of tasks still left. the ribosomes will be churning out vast quantity of various viral proteins. All these have to be arranged in proper order before assembling them into a complete daughter virus. The virus uses the protease to clip the viral proteins into their right shape and position. The copies of all the RNA codes and proteins must go inside a shell neatly enveloped by the circular envelop protein with spike proteins projecting like a crown. ( Pic). A thousand daughter coronaviruses are ready.  Its time to dissolve the cell and release the thousand new viruses. They are the new assasins and would invade thousand fresh cells. The task is successfully completed. She would also perish in the process. That is the rule of the RNA world.

The whole process takes only 10 hours.

The human ribosome are crooks. They knowingly make some faulty proteins. The mother virus is helpless. She has not carried any spell check program that will weed out the defective daughters. Time is precious and there cannot be any compromise with speed. Some of the defective daughter viruses will have to perish. But some defects will carry on to set up a different line of viruses that will be known as the Variants. May be that is for the better of the RNA world. Who knows ! 

I don’t know whether the mother virus has a drop of tear pouring as she shoos the thousand daughter viruses out before perishing along with the human lung cells.

The task is over. Thousand new viruses are released from one infected lung cell and entered thousand new cells. In a matter of half a day. By 5 days, the hapless sapien will be a bag full of virus if the process is not halted.

The Human Initiative:

Since the beginning of the life, so many plants and animals have evolved and perished. But only the Viruses and the Sapiens have stuck on. Not without reasons.

It took the Sapiens exactly two years to decipher the two equipments that the RNA virus specifically used for the invasion. One Protease and one Polymerase. It’s a matter of time before they would forge two inhibitors against both the two enzymes.

In November 2021, two drugs Paxlovid and Molnupiravir are authorised for use against the SARS COV-2 one acts against the viral Protease the other against the viral Polymerase.

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