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From a sandwich to a scream
From a sandwich to a scream
the ground and, like so many times before, finds its way through cracks and fissures and streams back to the oceans. In subsequent millennia, our molecule finds its way into a whale’s brain, an Antarctic ice sheet, a glass of water and a human heart. Later, it waters a pine tree. It sits for decades in the cellulose fibres of the tree’s heartwood before the pine is felled and turned into pulp. The molecule stays in place as the pulp goes through chemical reactions, manipulations and dryings until it finds itself locked inside a sheet of paper. That paper is printed with ink. It is cut, folded and stapled. The water molecule sits, motionless, at the end of a sentence, this very one. Alok Jha is the author
Traveller Energy Origin Your lunch Destination Your cells Duration Hours
of The Water Book (Headline, 2015)
a mosasaurus breathed into your stove
S
A
typical sandwich contains billions upon billions of buzzing electrons. The bonds they form hold together the sugar, carbohydrate, fat and protein we call lunch. The energy in those bonds will eventually power your body, but it can do you no good locked in a sandwich. Luckily, electrons have you covered. Our electron’s journey begins with a bite. Attached to a starch molecule, it is pushed from your mouth to your stomach and then small intestine. Its starchy home is torn asunder by enzymes from the pancreas, and now our intrepid electron is adrift on a molecule of glucose.
Traveller Carbon atom Origin A mosasaurus’s breath Destination A coal-fired power plant Duration 65 million years
ixty-six million years ago, a vast shallow sea covers swathes of North America – the Western Interior Seaway. A carbon dioxide molecule is expired into the tropical waters by an 18-metre-long aquatic mosasaurus. It embarks on a journey around the world, flitting between air and ocean, until…
66 mya
60 mya
35 mya
Geological forces lift the bottom of the Western Interior Seaway and the sea is replaced by subtropical lakes and swamps. Having travelled around the world, our carbon dioxide returns to North America and is absorbed by a swamp tree. The tree dies, locking the carbon atom inside.
Layers of decaying plants and river sludge pile up on the tree’s remains. Rising temperatures and pressures crush them into a hard, dark rock: coal.
Millennia pass slowly. Far above our carbon, the region begins to dry out. More and more sediment piles on top of the coal, burying it thousands of metres below the surface.
32 | NewScientist | 14 November 2015
electron transport chain. Like a boulder perched at the top of a hill, with a bit of a nudge, the electron tumbles from higher energy states to lower, releasing energy along the way. Enzymes manage the fall, stair-stepping the electron to ever-lower states. Energy released at each step is used to drive a pump. Protons are pushed, one by one, across a membrane in the mitochondrion and pile up on the far side. Like fans desperate to get inside a stadium, the protons have a single drive – to get back through the membrane. As they push through molecular turnstiles, the energy they release
glues a phosphate to an ADP molecule: adenosine diphosphate is turned into adenosine triphosphate. You may have heard of it as ATP. This is the cell’s ultimate source of energy. By the time the electron has bumped its way down to the end of
“Like a boulder perched on top of a hill, with a nudge the electron tumbles, releasing energy as it goes”
the chain, some 32 ATP molecules have been made. Drained, our electron joins forces with a leftover proton, and two of these hitch themselves to an oxygen to form water. Flushed out of the cell, the water molecule makes its way to the lungs and moistens your breath. But the electron’s energy lives on, in the form of ATP. When, a few hours after lunch, you stub your toe, it helps activate a muscle cell contracting the diaphragm. This expels carbon dioxide and our electron’s water molecule out of your lungs. The molecule shoots past your voicebox and out into the world as a cry of pain. MacGregor Campbell
sam chivers
It crosses into the bloodstream, passing briefly through the liver, to join the rush of cells, chemicals and plasma that complete a circuit around the body roughly every minute. Before too long it finds its way into a muscle cell. The interior of a cell is far from safe. The electron’s glucose raft is quickly cut into pieces by a 10-step chemical disassembly line. Hanging on to one of the pieces, our electron is now headed for the cell’s power plant: the mitochondrion. This is where the electron’s energy truly comes into its own. Inside, it will enter the final stage of its journey: a series of reactions known as the
10 mya
1970s
Tectonic forces shift and the crust begins to rise. The pressure lessens. Rivers flowing from the majestic Rockies slowly erode the rock above. Our atom is part of what will come to be one of the largest coal seams in the world: the Powder River Basin, stretching across Montana and Wyoming.
The ground trembles as huge machines tear out tonne after tonne of coal. Our carbon sees the light of day for the first time in 66 million years, and is headed for an entirely different, less peaceful destination.
In a furnace, millions of years of slow formation are reversed in an instant. The energy released by burning the coal briefly powers someone’s stove. The fire binds the carbon to oxygen atoms. As carbon dioxide again, it escapes through the flue and into the atmosphere with countless others like it. Many more millions of years will pass before it returns to its deep-earth hideaway. Catherine Brahic
14 November 2015 | NewScientist | 33
the ground and, like so many times before, finds its way through cracks and fissures and streams back to the oceans. In subsequent millennia, our molecule finds its way into a whale’s brain, an Antarctic ice sheet, a glass of water and a human heart. Later, it waters a pine tree. It sits for decades in the cellulose fibres of the tree’s heartwood before the pine is felled and turned into pulp. The molecule stays in place as the pulp goes through chemical reactions, manipulations and dryings until it finds itself locked inside a sheet of paper. That paper is printed with ink. It is cut, folded and stapled. The water molecule sits, motionless, at the end of a sentence, this very one. Alok Jha is the author
Traveller Energy Origin Your lunch Destination Your cells Duration Hours
of The Water Book (Headline, 2015)
a mosasaurus breathed into your stove
S
A
typical sandwich contains billions upon billions of buzzing electrons. The bonds they form hold together the sugar, carbohydrate, fat and protein we call lunch. The energy in those bonds will eventually power your body, but it can do you no good locked in a sandwich. Luckily, electrons have you covered. Our electron’s journey begins with a bite. Attached to a starch molecule, it is pushed from your mouth to your stomach and then small intestine. Its starchy home is torn asunder by enzymes from the pancreas, and now our intrepid electron is adrift on a molecule of glucose.
Traveller Carbon atom Origin A mosasaurus’s breath Destination A coal-fired power plant Duration 65 million years
ixty-six million years ago, a vast shallow sea covers swathes of North America – the Western Interior Seaway. A carbon dioxide molecule is expired into the tropical waters by an 18-metre-long aquatic mosasaurus. It embarks on a journey around the world, flitting between air and ocean, until…
66 mya
60 mya
35 mya
Geological forces lift the bottom of the Western Interior Seaway and the sea is replaced by subtropical lakes and swamps. Having travelled around the world, our carbon dioxide returns to North America and is absorbed by a swamp tree. The tree dies, locking the carbon atom inside.
Layers of decaying plants and river sludge pile up on the tree’s remains. Rising temperatures and pressures crush them into a hard, dark rock: coal.
Millennia pass slowly. Far above our carbon, the region begins to dry out. More and more sediment piles on top of the coal, burying it thousands of metres below the surface.
32 | NewScientist | 14 November 2015
electron transport chain. Like a boulder perched at the top of a hill, with a bit of a nudge, the electron tumbles from higher energy states to lower, releasing energy along the way. Enzymes manage the fall, stair-stepping the electron to ever-lower states. Energy released at each step is used to drive a pump. Protons are pushed, one by one, across a membrane in the mitochondrion and pile up on the far side. Like fans desperate to get inside a stadium, the protons have a single drive – to get back through the membrane. As they push through molecular turnstiles, the energy they release
glues a phosphate to an ADP molecule: adenosine diphosphate is turned into adenosine triphosphate. You may have heard of it as ATP. This is the cell’s ultimate source of energy. By the time the electron has bumped its way down to the end of
“Like a boulder perched on top of a hill, with a nudge the electron tumbles, releasing energy as it goes”
the chain, some 32 ATP molecules have been made. Drained, our electron joins forces with a leftover proton, and two of these hitch themselves to an oxygen to form water. Flushed out of the cell, the water molecule makes its way to the lungs and moistens your breath. But the electron’s energy lives on, in the form of ATP. When, a few hours after lunch, you stub your toe, it helps activate a muscle cell contracting the diaphragm. This expels carbon dioxide and our electron’s water molecule out of your lungs. The molecule shoots past your voicebox and out into the world as a cry of pain. MacGregor Campbell
sam chivers
It crosses into the bloodstream, passing briefly through the liver, to join the rush of cells, chemicals and plasma that complete a circuit around the body roughly every minute. Before too long it finds its way into a muscle cell. The interior of a cell is far from safe. The electron’s glucose raft is quickly cut into pieces by a 10-step chemical disassembly line. Hanging on to one of the pieces, our electron is now headed for the cell’s power plant: the mitochondrion. This is where the electron’s energy truly comes into its own. Inside, it will enter the final stage of its journey: a series of reactions known as the
10 mya
1970s
Tectonic forces shift and the crust begins to rise. The pressure lessens. Rivers flowing from the majestic Rockies slowly erode the rock above. Our atom is part of what will come to be one of the largest coal seams in the world: the Powder River Basin, stretching across Montana and Wyoming.
The ground trembles as huge machines tear out tonne after tonne of coal. Our carbon sees the light of day for the first time in 66 million years, and is headed for an entirely different, less peaceful destination.
In a furnace, millions of years of slow formation are reversed in an instant. The energy released by burning the coal briefly powers someone’s stove. The fire binds the carbon to oxygen atoms. As carbon dioxide again, it escapes through the flue and into the atmosphere with countless others like it. Many more millions of years will pass before it returns to its deep-earth hideaway. Catherine Brahic
14 November 2015 | NewScientist | 33