On a Sunday morning wander through the fields of Sulzbach, I couldn’t help but notice these things,
Ok, I thought to myself, those plants look to be doing OK, but surely showing that much root is frowned on by the more conservative members of the plant community.
Armed with nothing more than burning desire to know more about these confidently bulbous plants, I interrogated the internet. After hours of ethically borderline questioning, it told me that what I had in front of me was some kind of beet.
The beet it turns out (or at least one of its varieties) is grown in Germany thanks to my own personal favourite short statured, horse riding Frenchman – Napoleon. In response to the English refusing to share their sweet sweet Caribbean cane sugar with him, he supported research into of a cheaper sugar producing plant. His scientists presented him with bread made from beet sugar rather than cane sugar, and he was so impressed that he ordered that 32 000 hectares of the stuff be planted in France. The crop proved so popular that two centuries later, a third of Europe’s sugar comes from the beet.
The sugar is stored in the bulbous root thing that makes the plant look so awkward. I understand why humans might want to grow a plant with a desert for a root, but what on earth is in it for the beet? and how is it making sugar from the things it has access to? – it’s not like the farmers are feeding it jelly beans and toffee.
In order to understand this, first I need to be more precise with my language, sugar, unfortunately isn’t an accurate enough word to describe what the beet is storing. It is hoarding a compound called sucrose. And it’s doing this for the same reason that humans want to eat the stuff. Sucrose is a fantastic way to store energy, energy that the beet can use to grow leaves, keep photosynthesis running and ice skate1.
I’m an organic chemist, and while all that biology is interesting to me, what I really want to know, is how does the little chemical factory that is the beet, make sucrose from the building blocks it has access to. The pdf below shows my attempt to visualise the first couple of steps of this process. I’m using simple shapes here to represent atoms, and lego men to represent enzymes. If you’d like to know more about these things, there are more educational tools on the web than you can poke a stick at, but you might start here, or here or even here.
The first thing that happens is that the plant takes in water and carbon dioxide from the environment. Lego man one adds the carbon dioxide to the pre-prepared compound at the top of the graphic. I truly wish there was a simple explanation for where that top compound comes from. The way I’m telling this story is a bit like if I told you that Statue of Liberty was built in two stages – first, aliens teleported a giant metallic woman to earth, and then some industrious lego men thought she looked weird with her hand outstretched for no reason, so they built her a torch to hold from things they found lying about.
The Happening has a more satisfying narrative than that.
Unlike The Happening, this story is going to have many many sequels, and hopefully one day, I’ll be able to show you that that top compound is also made from simple building blocks.
Anyway, back to sucrose, the new compound is quite unstable. With the help of some water, and a second lego man, the compound splits in two. This gives two new compounds, which could embark on the epic journey to become sucrose.
I don’t use epic lightly here, these compounds face the kind of insurmountable odds that would make Frodo turn around and head for Bag End. Much like Frodo, at some point on their journey the compounds will probably be burnt alive by Daenerys’ dragons in the sands of Dune.2
As the months and years go by, I hope to show you the more death defying parts of this journey, but there’s every chance I’ll get distracted by some other shiny biochemical pathway….
Is that a lysine over there?
- Sure, be skeptical about the beets on skates thing, but let’s just remember which of us is writing the authoritative blog post here.
- OK, I didn’t actually read past the Tom Bombadil section, I figured the books couldn’t possibly get any better, so why spoil the memory of a perfect story.