Tag Archives: biology

Writing prompt: cousins day

Time: 7 minutes. Click here to go to my list of prompts.

“Cousins day” (Inspired by this list of silly holidays.)

(author’s note: I am not a biologist, so all the biology in here is just fun and spitballing!)

The Tasmanian Flu wasn’t a type of flu at all. No one knew then, sixty years ago. It was an engineered disease that got lucky enough to absorb a favorable mutation from a wild bacteria. It didn’t develop in Tasmania. We started calling it the Tasmanian Flu after no one would admit to the disease, but it was everywhere. Well gosh, it must’ve come from Tasmania. That’s where devils come from, right?

Either you were susceptible to TF, or you weren’t. A mother would catch the disease, then all her children, but not her husband or her in-laws. Quickly, they isolated the genes responsible for susceptibility. The fear was, if it infected enough people, it would absorb another wild mutation and gain the ability to infect anyone. After Putin died of the illness, conspiracy theorists speculated that it was a targeted assassination of the Russian despot gone awry.

That didn’t to the Cousins.

That’s what they called us. They rounded up those susceptible, the Cousins, and they put us in bio-containment camps away from everyone else. We had good care. They tried to keep the infected isolated from the merely susceptible. But it didn’t work, and TF has a 50% fatality rate even with novel treatment. Then there were the side effects.

I know 200 digits of pi. I didn’t try to remember them, and before TF I had no head for numbers. With minimal training, I found I could make sense of complicated geometries and had inexplicable intuitions as to the solutions of complex systems.

For 60 years, we made up for the loss of our cousins with our gifts. There are fewer of us than there once were. And now, some whisper that perhaps TF could be useful.

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Writing prompt: invasive species

Time: 7 minutes. Click here to go to my list of prompts.

“Invasive species”

Years ago, I watched time-lapse photography of plants growing. Plants move and respond to stimuli and avoid pain like animals, the narrator said. They just do it on a different time scale. That documentary made me wonder what the world seems like to a plant.

Reading the news the other day, that documentary came to mind. The tenta plant has been making its way up from Mexico. Here in the Shenandoah we knew we’d be safe; we have winters here after all. Plants adapt over time, but winter is a mighty thing.

Somehow, the tenta adapts faster. Scientists are fascinated by it the way they always are by hazardous things, like a kitten with a grenade. Some have compared it to reverse transcription viruses like HIV, somehow it has some ability to incorporate genetic attributes of other plants. Surrounded by winter-hardy plants, ten thousand of these plants could try ten thousand combinations.

There are indications of new traits to the plant, as it grows further into more densely settled regions. It was never an irritant like poison ivy, but now it is. Some have nettles.

I remember watching those vines frantically reach toward the light, in some way we can’t understand knowing and feeling what they wanted. Or the ficus tree, slowly growing the life out of its host. I couldn’t help but wonder if the tenta plant had such an awareness to accompany its novel new ability, and what that might hold for the future.

Fun Science: Enzymes

An enzyme. Spirals and sheets and strands indicate different kinds of structures. (from Wikipedia)

Enzymes are the catalysts of the body, helping to facilitate chemical reactions that would be very slow or unfavorable in their absence. In a previous post, I discussed how platinum lowers the activation energy barrier for desirable chemical reactions in a car engine, among other places. Enzymes do the same thing, but they are much more selective. Platinum can act on millions of molecules. Enzymes are shaped so specifically that they act only on one molecule. Because of this, enzyme catalysis is often compared to a lock and key–only one chemical is so perfectly shaped as to fit into the active site of the enzyme.

Enzymes are mostly proteins, which are made of hundreds of amino acids with several layers of structure. Our DNA is coded so that enzymes can be assembled from the instructions. The “primary structure” is the sequence of amino acids strung together. The shape of local groups of amino acids gives the “secondary structure”; some combinations tend to coil, others tend to be flat (see the picture at the top of this post). This is due to interactions between the amino acid groups; for example, ionic groups might attract or repel each other. The “tertiary structure” is the structure of the overall molecule, also called the “folding”. We can reproduce the primary and secondary structures in the lab; the folding is harder, because for most sequences of amino acids, there are several possible structures. In the body, the protein is assembled in such a way that it conforms properly. We are mostly still unable to synthesize proteins and enzymes. We usually use bacteria and fungi to make them, when possible.

Enzymes are essential to life. They aid in digestion. Many diseases are caused by the lack of a single enzyme. People with lactose intolerance lack lactase; the deadly Tay-Sachs disease is caused by the lack of hexosaminidase A. In Tay-Sachs, a waste product of cellular metabolism builds up in the brain. Without the enzyme to accelerate its break-down, the waste product builds up to intolerable levels. We can obtain hexosaminidase A, but we can’t therapeutically deliver it to where it is needed in the brain.

You probably already knew that the human body is a remarkable machine. But I hope this brief overview of enzymes gives an appreciation for this one small aspect. Happy digesting.