Cells, complexity and the meaning of life and death

Three mitochondria surrounded by cytoplasm. Wellcome Images

Three mitochondria surrounded by cytoplasm. Wellcome Images

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When Nick Lane told a Packed Lunch audience that his latest theory on the birth of complex life had been nine months in the making, it seemed a fitting gestation period. Unfortunately he had just half an hour to tell us about it.

Nick is a writer and biochemist at UCL, where he holds the first Provost’s Venture Research Fellowship in the Department of Genetics, Evolution and Environment, and is a founding member of the UCL Consortium for Mitochondrial Research. His research on the role of bioenergetics in the origin and evolution of complex life is fascinating.

Bioenergetics is the study of the energy flow through the body. Our energy comes from the molecules in the food we ingest. This energy is converted as part of respiration by mitochondria, the cellular ‘power plants’, into a molecule called ATP that can transport chemical energy within cells, enabling the chemical reactions that support life.

Nick wants to know exactly how and why mitochondria came to be in complex cells. The first forms of life were prokaryotes – small, simple cells. Eukaryotes, larger cells with mitochondria and other organelles, came after prokaryotes on the evolutionary timeline. It is supposed that eukaryotes evolved from prokaryotes. How, and why? It is generally believed that at some point in history, a large prokaryotic cell, such as a phagocyte, engulfed an ancestral form of a mitochondrion that once existed as a free-living organism. There is much argument and acrimony over how, when and why this happened.

After gaining a PhD in biochemistry, Nick spent ten years ruminating on these questions as a professional writer, during which time he “rove across the world – a wonderful freedom”. He has authored three books: ‘Oxygen: The molecule that made the world‘; ‘Power, Sex, Suicide: Mitochondria and the meaning of life‘; and ‘Life Ascending: The ten great inventions of evolution‘ (which has just been awarded the Royal Society Prize for Science Books 2010). But through his exploration of these topics, he found that “time and time” again his own understanding “fell flat on its face”. It was time to go back to the lab.

Nine months ago Nick started scribbling on the back of an envelope. He was sketching out an idea that related extra energy to extra genes. At the moment of endosymbiosis, when an ancestral mitochondrion partnered with a eukaryotic cell, the genes from the mitochondrion provided the large cell with the “raw material for evolution”. Nick now supposes that the extra energy provided by the mitochondrion enabled the cell to support these extra genes. Whereas prokaryotic cells do not have the energy to carry large amounts of DNA, eukaryotic cells, with their mitochondrial powerhouses, can. This theory will be published in ‘Nature’ after five months of review. Nick says “some people will hate this paper”. Argument and acrimony.

Nick is also interested in the role mitochondria play in disease, and particular disorders related to ageing. Free radicals are an essential byproduct of the respiration process that happens in mitochondria. They ‘leak’ from mitochondria, which can cause damage in the body. Other scientists are researching free radicals as the causes of cancer, Parkinson’s disease, schizophrenia and Alzheimer’s. Nick is looking into how antioxidants and calorie restriction diets might be able to ‘mop-up’ free radicals and reduce the number that leak from mitochondria, thus reducing the damage they do. This work is ongoing. For the moment, it seems that mitochondria hold some of the secrets of both life and death.

Eating, walking, stretching and bubbles

A Packed Lunch event at Wellcome Collection

A Packed Lunch event at Wellcome Collection

Can summer be over already? It’s sunny outside as this post is written, but autumn must surely be upon us soon, because we’ve just unveiled our new season of events. It’s quite a selection, ranging from London-wide health issues to microscopic bubbles, taking in skin both stretchy and perfect, packed lunches, delicious suppers and several intriguing strolls. Booking opens tomorrow at 14.00: our events fill up fast, so be ready to book online. And all (except the excellent value Supper Salons) are free.

Nursing and midwifery take over the entire building for an evening in Handle with Care, dedicated to the science and senses of caring professionals. Sick City? takes the form of a balloon debate: four experts each put their case for what they consider to be London’s public health priority. You the audience decide who wins, in a series of votes. And the Pars Foundation take an oblique look at our remarkably flexible skin in their Treats on Elasticity event (more on Pars and their stretchy work in a future blog post).

Lunchtimes will get interesting, as our Packed Lunch series of talks with local scientists returns. Taking her cue from our current exhibition, Isabel Jones kicks off by talking about her work repairing the skin’s delicate structure at the Chelsea and Westminster Hospital’s burns unit. UCL’s Nick Lane looks into how complex organisms evolved from simple bacteria (it’s all about the mitochondria), and Peter Ayton from City University explains how we make decisions in a bewildering and complex world. Then it’s back to UCL with Eleanor Stride, who works with microbubbles. It all sounds unmissable, but if you can’t get there in person, the ever-reliable Packed Lunch podcast will be there for you to catch up.

If dinner is more your thing, then Supper Salon will be right up your street. We skip straight to dessert with jelly-makers extraordinaire Bompas and Parr, whose gelatinous creations do so much more than wibble-wobble on your plate. But if you prefer giant crabs to jelly you’ll be in good company with our next guest, Robin Ince, a writer, comedian and collector of very bad literature including tales of the aforementioned crustaceans.

Having filled yourself up with food and ideas, some exercise might be in order, and what better way to take it than with our series of medical walking tours guiding you through the hidden corners and recondite histories of Bloomsbury. Explore the medical marketplace in ‘Conspicuous Consumption’, take a walk on the dark side with ‘Dead Famous’, recall the poverty in Bloomsbury’s history ‘In Sickness and in Health’, and get a taste of the scientific and occult in ‘Secret Bloomsbury’. Walks are led by Richard Barnett, author of Medical London, Strange Attractor‘s Mark Pilkington, and the Wellcome Library’s very own Ross MacFarlane. If you’re taking photographs on the walks (or if you take photographs of medical sites and  scenes anywhere in London), we’re always grateful if you add them to our Medical London Flickr pool, helping us build up a composite contemporary picture of London’s illness and cures.

And don’t forget our events looking at the Wellcome Library and its collections. Investigate the relationship between our heads and our hearts in Mind and Body: Heart and mind, and discover the multimillion-pound industry that feeds our Quest for Perfect Skin. Find out more about Henry Wellcome himself, and about William Morris’s collection of manuscripts in the Library. Focus on lurid tales of London life in Anatomies of London, and the 19th-century enthusiasm for ‘reading faces’ in London Faces. And then see Africa from another angle with a special tour for Black History Month.

Looks like a busy autumn for us. Hope to see you here soon.