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Scientists Marvel at Enzyme Efficiency

Many chemical reactions occur from simple collisions.  One atom may have spare electrons, another may need them.  Attracted by each other’s valences, the atoms collide and bonds form.  Not so with biological enzymes: these molecular machines owe their efficiency to their three-dimensional shapes.  Made up of hundreds of amino acids, enzymes have “active sites” where […]

Biological Complexity Continues to Astound

There’s more going on in your thinking apparatus than you think.  New scientific discoveries continue to unfold new layers of complexity and control.  Here are a few examples: Meta-code:  Your body has codes directing codes.  Geneticists were initially dismayed to find only 20,000 to 30,000 genes in the human genome.  “We were expecting that something […]

Paley’s Watch Found in Bacteria

A clock with cogs, gears and ratchets that keeps accurate time – what more could William Paley wish for?  The 18th century natural theologian used the illustration of stumbling upon a watch in a heath as an example of reasoning from design to a Designer – as from watch to watchmaker.  Skeptics like David Hume […]

How Cells Thread a Needle

Your challenge today is to invent a machine that can push a wet noodle through a straw.  It can’t pull it.  First it has to grab the end, then push it through without breaking it.  Oh, and there’s a catch; the straw has a plug at the far end and a constriction inside.  Give up?  […]

Selling Stem Cells to Voters

If you thought embryonic stem cell research became moot after researchers found they could induce skin cells to become pluripotent, these news stories show the push is still on to open up more funds for embryonic stem cells.  A ballot measure in Michigan is a bellwether for how scientists still feel about these tantalizing objects […]

Deep Life Is Right at Home in Total Darkness

It seems every year scientists find organisms thriving in environments thought too inhospitable for life.  A new word was coined for these organisms: extremophiles – lovers of the extreme.  Two recent discoveries push the envelope of extreme environments almost to the deep limit. Pressurized fish:  The bottoms of the deep ocean trenches of the Pacific […]

Cellular Machines Work Like Cameras, Winches and Turboprops

The discovery that cells are filled with molecular motors is one of the major achievements of late 20th-century molecular biology.  Biochemists routinely use the word “motor” when describing cellular processes, because, in fact, machines made of protein actually do use energy to perform work.  Now we have a new hybrid science – biophysics – that […]

How Chromosomes Pack Without Exploding

When preparing to divide, a cell has to copy all its DNA accurately and pack it into chromosomes.  A professor at U Chicago told Science Daily this is “like compacting your entire wardrobe into a shoebox.”  The cell has another difficulty in this compaction process, though: DNA, being negatively charged, resists packing.     Eukaryotes […]

Membrane Switches Keep Your Brain Humming

Tunnels with rotating gates and rocker switches – this sounds like mechanical engineering.  It’s the machinery that helps power your brain, reported scientists from UCLA and the Pasteur Institute.     Their paper in Science described the structure of just one of many kinds of membrane channels.1  Cell membranes are lined with elaborate one-way gates.  […]

Adult Stem Cells Race Ahead; Embryonics Falter

Major advances are being made with induced pluripotent stem cells (iPS), stem cells reconstituted from adult tissues, while interest in embryonic stem cells (ES) seems to be drying up.     Both Nature and Science reported advances in iPS technology last week.  Nature reported that the number of factors needed to reconstitute pluripotent stem cells […]

Cellular Trucks Use Moving Highways

Imagine how cool it would be to get in your car and have the road do the driving.  The highway would stretch or shrink, moving this way or that, till you saw your destination and hopped off.  That appears to be what the cargo-bearing motors do in the cells in your body.  A new paper […]

It’s Networks All the Way Down

New ways of seeing biology are finding life is full of networks.  At both ends of the complexity scale – from humans to bacteria – complex interactions are the rule.  Two teams studying different phenomena had the same reaction – astonishment. Bottom-up complexity:  Who would have thought one of the simplest life forms has a […]

Amazing Cell Tricks: Contour Map Navigation

Watch a cell divide, and if things go well, it always divides in the middle.  How does a cell figure out where its middle is?  It follows its contour map.  PhysOrg titled its entry, “Dividing cells find their middle by following a protein ‘contour map’.”     Cell division, or cytokinesis, is a precisely-controlled operation […]

Bacterial Flagellar Motor Has a Protein Clutch

The bacterial flagellum, the whiplike outboard motor that has become an icon of intelligent design, has another artificial-looking part: a clutch.  Science reported this in “machine language” as follows:1 The bacterial flagellum, powered by a motor that generates 1400 pN-nm of torque, can rotate at a frequency of greater than 100 Hz.  EpsE [the clutch […]

Magic Box in the Cell Baffles the Experts

Put a string of amino acids into this magic box, and it comes out all precisely folded into a protein.  How does it do it?  A molecular machine described by Science Daily has scientists baffled.  Ironically, its name is TRiC.     TRiC is a chaperonin, a member of a class of molecular machines that […]
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