Cell Biology

... from active transport to vesicles

Inner Life of the Cell

For any who have not yet realized that the biology of cells can be fascinating – and aesthetic – Harvard University has sponsored an animation of the "Inner Life of the Cell" (HiRes, LoRes).

Unfortunately, the Internet-released version lacks a commentary soundtrack, settling instead for a music background that restricts the experience to pure aesthetics in the absence of explanation. My attempt at interpretation follows:

The animation opens with the rolling adhesion of a leukocyte within a blood vessel. The surfaces of two cells are shown adhering at contact points between adhesion molecules (selectin-saccharide).

We enter the cell and see a lipid raft, with its embedded sphingolipids and phosphatidyl choline(cholesterol+proteins), floating within the plasma membrane. Next we see a multi-protein focal contact, and then the cytoskeleton. After glancing back at the sub-plasma membrane 'geodesic' microfilaments, we pass down throught the cytoskeletal lattice and see actin microfilaments assembling, then depolymerizing after attachment of a protein (gelsolin?).

Next we see assembly and disassembly of tubulin. This interesting sequence is followed by my favorite segment, which is kinesin dragging an endosomal vesicle along a microtubule as kinesin-bigfoot 'walks' along the tubulin that is radiating from a centriole pair. A fellow kinesin, in the background, actively transports an endosome in the opposite direction.

Next, we approach the nuclear envelope with its embedded nuclear pore complexes. Several mRNA molecules with attached proteins exit the nucleus through the pores and assemble into loops within the cytoplasm, where the mRNA is scanned for a start codon, and is then translated into new polypeptide/protein chains by a ribosome. Globular proteins dimerize and tumble toward a mitochondrion.

Further translation injects a nascent protein chain through a pore into the endoplasmic reticulum as 'bigfoot' continues to clomp along tubulin, dragging a vesicle behind. Next, we see the Golgi apparatus budding vesicles before our plodding kinesin reaches the plasma membrane and proteins are released into the ECF by exocytosis. The newly synthesized integrins float on a lipid raft before unfolding into their active conformation, whereupon they snare a passing leukocyte and induce extravasation.

Happily, an extended version of the animation, complete with commentary, is now available on YouTube.

See a video of medical animator David Bolinsky describing the making of Inner Life of the Cell. More Cell Biology Videos.

The creationist mucusballs at the Dissembly Institute have plagiarized the footage, renamed it The Cell as an Automated City (presumably because that analogy is within the conceptual grasp of creationists), removed its credits, and are passing it off (implied) as Behe's research into the complexity 'created' by the IDer (aka God). The IDiots collect donations from credulous creationists as the DI Fellows pretend to conduct scientific investigation of IDiocy. I sincerely hope that Harvard University and XVIVO sue the pants of the IDiots, just as I'd like to see them tried and convicted of their plagiarism at the Kitzmiller vs Dover School Board trial.
See Creationist crooks pilfer Harvard's work . DI Fellows-- EXPELLED for plagiarism . Plagiarism and Intelligent Design .

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