Cells Know Their Physics

At the microscopic level of cells, forces come into play that are unfamiliar to us at the macro level: quantum mechanics, Brownian motion, and subtle elastic forces that we might overlook.  Two recent papers in the Proceedings of the National Academy of Sciences explored physical mechanisms cells use to good advantage.  Good thing cells know […]

Automatic Turnstiles Found in the Cell

One of the things students learn about in high school biology classes is active transport: the ability to control flow through a semi-permeable membrane.  Contrary to osmosis, in which the flow goes naturally from high concentration to low concentration, cell membranes employ active mechanisms to push or pull the molecules through their membranes according to […]

Hairy Bacteria Walk and Talk

Little hair-like projections on some bacteria, nearly invisible with light microscopes, are not just for decoration.  They do amazing things – as a pair of recent discoveries brought to light.  They help bacteria walk and talk. But can they dance?  Bacteria swim, but they also land on surfaces – and when they do, they put […]

DNA Performs the Linking Rings Trick

Those who love a good magic show should be aware of a world-famous trick going on inside their own bodies.  The “Chinese linking rings” trick is done by a team of protein magicians in the cell – but it’s not for entertainment, it’s to repair damage that could lead to cancer.     PhysOrg echoed […]

More DNA Repair Wonders Found

One of the most phenomenal discoveries since the structure of DNA was revealed must surely be the discovery of multitudes of protein machines that repair DNA (01/04/2002).  The repair machines are themselves coded by DNA, but DNA would quickly decay into nonsense without them.  Another “fundamentally new” repair mechanism was discovered by researchers at Vanderbilt […]

Big Gains for Adult Stem Cells Announced

Ever since Shinya Yamanaka figured out how to coax skin cells to become pluripotent stem cells in 2007 (something for which he is being considered for a Nobel Prize, see PhysOrg), other researchers have been improving on his idea.  Three big gains were announced recently.     PhysOrg and New Scientist reported work by Derrick […]

Cosmic Accidents Are Not Scientific Explanations

Sunday Meditation Oct 3, 2010 — The classic understanding of science is that it explains things with reference to natural laws, makes predictions, is testable, quantifiable, and falsifiable.  Depending on the branch of science, many researchers still attempt to hold to those ideals.  Eugenie Scott put it this way: “modern science operates under a rule […]

Ethics Shmethics: Scientists Obsessed with Embryonic Stem Cells

With non-controversial adult stem cell research zooming along, like finding ways to prevent adult stem cells (ASC) from aging (PhysOrg), providing hope for leukemia patients (Science Daily) and giving mastectomy patients a chance for beauty once again (Science Daily), why are so many scientists adamant about keeping embryonic stem cell research on the public dole? […]

Mere Biochemistry: Cell Division Involves Thousands of Complex, Interacting Parts

In biochemistry, the stem -mere means “part” (as in centromere, telomere) and -some means “body” (as in chromosome, ribosome).  Biochemists are learning that these cell organelles are not -mere bit parts, but -some fit bodies. Telomeres and chromosomes:  PhysOrg reported that the chemical “caps” on the end of chromosomes, called telomeres, have a special code […]

Piston Engine Joins Rotary Engine in Cells

The rotary engine ATP synthase has been discussed frequently in these pages (e.g., 12/22/2003, 08/10/2004, 08/04/2010) as an exquisite “molecular machine” that produces the cell’s energy pellets (ATP) with a rotary, turbine-like mechanism.  Now, a piston-driven engine has been found at work in every cell’s energy factory.     ATP synthase operates at the end […]

Synonymous Codons: Another Gene Expression Regulation Mechanism

Some words in English have alternate spellings, but sound the same.  If the sound is the same, how would a recording device tell them apart?  Would it make any difference?  It shouldn’t, but now scientists are realizing that genetic codons spelled differently can influence the protein formed – even when the spellings, called “synonymous codons”, […]

Nerve Traffic Cop Identified

What makes signals go in one direction in neurons?  It’s important, because a reflex signal from a bump on your knee needs to go in the direction of the controlling muscle and on to the brain, not any which way.  Is there some kind of traffic cop that directs the placement of “one way” signs […]

Embryonic Stem Cell Researchers Reeling from Judge’s Decision

Political conservatives have often been stunned by lone judges overturning the will of the people.  This time, liberals in support of embryonic stem cell research are reeling from the decision of a federal judge that halts funding of such research that was recently energized by the President.     Federal Judge Royce Lamberth’s August 23 […]

Clever Animals Amaze and Inspire

The living world is an endless source of wonder and inspiration.  There’s an octopus that does a convincing imitation of a flatfish (Science Daily, Live Science), and a red crab species that emerges from its lethargic life around Christmas and migrates miles to the sea by the millions (PhysOrg).  There’s a tiny frog that can […]

Specialized Molecules Make Cells Work

Reports continue to show that vital cell processes depend on finely-tuned proteins and RNA molecules.  Most of the papers that discuss these specialized molecules fail to mention how they might have evolved, as shown in three papers in the recent issue of Science. Walker with muscle:  A paper by Kaya and Higuchi from the University […]
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