World War Vitamin Z
On the photosynthesis of Vitamin D, the Rubisco tragedy of the plant kingdom, Tapioca Macaroni and Zombie Cicada sexbots
Namaskaaram,
Since Sidin was busy using his advanced intellect, savoir-faire, and creative musculature to author witticisms such as this, and I would like to apologize in advance, this, the Salem Junction newsletter got delayed again, but to paraphrase a famous dialogue from Tamil films, even when Sidin is late, he simply does a global find-and-replace of the word “late” to “latest”, and all is hunky-dory.
Rubisco Disco
Our first story is about our magnificently brown, gloriously melanin-drenched Indian skins. When exposed to the sun, it undergoes a gradual tan that makes freckled white people jealous. But rather ironically, the darker the skin, the less efficient it is at doing something pretty important. Synthesizing Vitamin D.
The fact that humans photosynthesize Vitamin D by exposing our skin to the sun is, by itself astonishing. In general, we associate photosynthesis with plants. I mean, who has the patience to sit in the sun just to make some mildly important vitamin? Trees do, not us. As proud mammals, we pride ourselves on letting plants do the hard work of actually using energy from sunlight to make useful stuff (like say, a potato) that we can quickly cut, double-fry them in goose-fat and enjoy French fries that are really Belgian in origin. In fact, the very evolution of the entire animal kingdom is predicated on this exploitative relationship of letting plants do the hard work of making carbohydrates that we mobile critters can munch on rather efficiently. The entirety of the animal kingdom has a very British empire vibe about it.
But let’s take a step back and dig into this a little bit. That our skins do some photosynthesis goes back to the very first phytoplankton that did this in the earth’s oceans 750 million years ago, and it is one of the few things that connect us to the world of plants. Why did these plankton do this? Good question. Vitamin D, it turns out, is kinda crucial for the absorption of calcium, which, it turns out, is kinda important for eventually growing things like bones. But plankton are single-celled floaty things that do the other, more important bit of photosynthesis - using sunlight to make glucose. Why on earth do they need calcium, you might ask? Good question, and scientists, as always, have the perfect answer for it - they are not sure.
They think Vitamin D might have acted as a sunscreen of sorts. But, fortuitously for all of us animals, that was an important skill that allowed life to crawl out of the oceans and onto land. You see, tons of calcium are already dissolved in the ocean, so sea creatures don’t really have a problem. On land, however, calcium is hard to come by, so animals need to be super-efficient at using every bit it can find in food, and that’s exactly what Vitamin D does - makes calcium more available for cells to use.
But the more interesting story is the other, more important version of photosynthesis - the one that, well, makes life possible on the planet. The actual chemistry could fill an entire textbook, so the TL;DR version of the reaction is that plants use a molecule called Chlorophyll to trap energy from sunlight to create a 5-carbon molecule that, through a series of complex steps, is converted into the 6-carbon molecule, Glucose. And one of those complex steps involves plants taking carbon dioxide from the air and using that carbon atom to turn that 5-carbon molecule (called RuBP) into Glucose. Turns out that is a rather hard thing to do and involves a broker enzyme with the suave and debonair name, RuBisCO.
Now, have you ever wondered why plants don’t move much? Like, even if they are rooted to a place and so on, why haven’t they evolved tentacles that can, for instance, pick up a passing deer and ingest it for some extra protein? Why don’t we have Ents by now, walking trees that could do stuff like throw rocks at oppressive colonialist regimes? In short, why is everything in the plant kingdom in 1000 fps slow motion?
The root cause, it turns out, is our man RuBisCo who is all hat and no cattle. He is rather terrible at his job. To put things in perspective, enzymes catalyze about a thousand reactions every second. I mean, that's the whole point of an enzyme - to help move reactions along. RuBisCO? 1-2 reactions per second. That bad. So you might be wondering - Come on. Plants have had 600 million years to fine-tune this, so how on earth has some plant (or plankton) not figured out a way to throw this guy out and replace him with someone more productive?
It turns out that we are being rather harsh with RuBisCO because the ultimate cause for its inefficiency happened way before land plants evolved. We have to go back to photosynthesizing bacteria 3 billion years ago. You see, back then, there wasn't much oxygen in the atmosphere. The invention of photosynthesis was so game-changing that it was the singular cause for pretty much all the oxygen we have in our atmosphere. And guess what, RuBisCO evolved in a low oxygen world.
And photosynthesis was so successful so fast that it couldn't hit the undo button on one small problem - RuBisCO works terribly in high oxygen environments, and ends up producing all manner of useless molecules the plant doesn't need. Imagine a Ferrari, but with an auto-rickshaw gearbox that cannot be swapped out easily.
And this, folks, is why plants take such a long time to go about their lives in general. Their entire lives are choked at the neck by this one enzyme. This is why we don’t have plants that walk, grab passing animals with tentacles or do disco. Blame it on RuBisCo.
Macaroni Bhagavan
Hello! Oh my god. Ashok’s bits of this newsletter have been sitting here for days waiting for my bits. Hopefully today I will be able to make my bits combine with Ashok’s bits. Aur bits bane hamara etc.
Really guys. On the face of it, Salem Junction seems like this slick production full of tightly edited banter and penetrating research. But in reality, it is just complete and total chaos (me) that somehow manages to get done every week (Ashok) just in time for the Spaces session. Phew. What I am saying is that I am the Nehru of this thing whilst Ashok is the Patel. (AT LEAST I HAVE A GIANT ASS STATUE DEDICATED TO ME. WHAT DO YOU HAVE EH? A UNIVERSITY THAT DOLES OUT Ph.D. DEGREES IN ANTINATIONALISM)
Speaking of Nehru, my first story this week was about the time Kerala was driven to uncommon desperation as the state sought to feed a starving population. This was in the years shortly after Independence. WW2, as we perhaps know, was already a time of terrible famine in India. Independence didn’t exactly change that. Within a few years Kerala was producing only about half the rice it needed to feed its people.
This was not, of course, an entirely new problem. In the years before, Kerala’s kings had tried to convince their people to switch at least some of their rice allegiance to the wheat-partly. One king even set up a wheat promotion department, complete with vans that went out distributing samples, recipes, and blaring wheat-ful messages from loudspeakers. The impact was long-lasting but very limited. (One of our Salem Junction co-passengers later suggested that these campaigns helped to popularise the use of semolina and the (Ashok edit: unfortunate) habit of eating of upma in Kerala.)
By the late 50s, Kerala had a serious rice problem. This is when someone came up with an idea that the Kerala government took up enthusiastically, albeit briefly. And that idea was: why not make fake rice from tapioca? Tapioca was available abundantly. Why not turn this tapioca into rice grain-shaped pellets that could then be used as a rice substitute? All over India, food scientists took up this challenge with gusto mone dinesha. And came up with an elegant two-part solution. Part 1: they would use Italian pasta-making equipment to turn tapioca flour mixtures into synthetic rice grains. And Part 2: they also came up with the ideal formula for this mixture: A mixture of either 80–90 parts tapioca flour, with 10–20 parts of peanut flour; or tapioca, peanut, and semolina, in proportion 60:15: 25; it is baked into shapes resembling rice grains or macaroni; developed in India. Also referred to as synthetic rice. (The Italians, mind you, already have a rice-shaped pasta variety called orzo. So this was, on the face of it, an elegant solution.)
Meanwhile, nutritional scientists carried out extensive research into the nutritional benefits of tapioca. Papers were written and very serious research carried out.
Meanwhile, the Kerala government not only began procuring tons of this synthetic rice, but also drew up plans to import massive pasta plants from Italy. And then… the entire idea lost steam. Why? Well first of all nobody actually liked the synthetic macaroni-rice. So much so that chief minister EMS Namboodiripad was mockingly referred to as ‘Macaroni Bagavan’. But more importantly, the green revolution was just around the corner and so was a miraculous uptick in rice output.
Thus famine was averted but without resorting to the vagaries of… synthetic rice. Adipoli.
Zombie Cicadas
A few weeks back, billions of Brood X periodical cicadas emerged after chilling for 17 years under the ground all across the Eastern US to find mates, produce the next generation of cicadas, and proceed to mostly be eaten by a host of predators who go at them as I do at the all-you-can-eat-chaat buffet restaurant. But by far the most astonishing organism that waits for the cicadas to emerge is a fungus named Massospora cicadina. Normally, one expects predators to do things like catch and eat prey. Some lay traps and wait for prey to fall into them. But not even the most imaginative author of diabolical pulp horror books could have written the story of how this fungus goes after cicadas.
For starters, the fungal spores spend the same 17 years in the soil and wait for the cicada nymphs to emerge. Some of them get infected on their way to the surface. The fungus then proceeds to colonize parts of the cicadas’ abdomens and genitals (which mostly fall off) and then, if you think this wasn’t horrific enough, proceeds to produce a brain-altering cocktail of amphetamines and psilocybin (of magic mushrooms fame) that turns the infected cicadas into zombie sexbots, who despite the lack of genitals will proceed to try and mate with as many cicadas as possible in what is best described as the air-guitaring version of sex, and spread the spores to as many bugs as possible.
Black Spartacus
Thanks for that delightfully wholesome story Ashok. I will convey it to my cousin in Kottayam, Cicada Chacko Thomas. Speaking of Zombies, I wanted to round off this edition of Salem Junction with a book recommendation. Sudhir Hazareesingh’s excellent Black Spartacus has just won the Wolfson History Prize. It is a biography of the great Haitian leader Toussaint Louverture, but it is much much more. And since the word Zombie is of Haitian origin, it makes for a nice elegant little connection. Also, we briefly talked about Wade Davis and his highly controversial book The Serpent and The Rainbow. And also of the Haitian man named Clairvius Narcisse who claimed he’d been zombified for a couple of years.
It’s all very mysterious and controversial and well worth a look.
(Also, before I go, I really must recommend another book that was on the Wolfson shortlist this year: Judith Herrin’s Ravenna. Amazing. And such beautiful pictures.)