PHYC452Biophysics:Interactions

Life at Low Reynolds Number

Here's a link to a talk given by E.M. Purcell discussing "Life at Low Reynolds Number". It seems to be a good addition to what we talked about in class on Monday. Life at Low Reynolds Number

Kathrin: I don't know if people have noticed Kevin Cahill's corn syrup demo for laminar flow at low Reynolds number. I really like this demo. You should check it out if you haven't seen it yet. Go to this site and select either /flash/viscosity.phtml to see video on server or /flash/viscosity.flv to download it. Hope you like it. By the way this is demonstrating fluid flowing in layers. The droplets don't actually mix... if you looked down from the top you would have seen concentric rings of color.

Online Searching of "Molecular Biology of the Cell"

Molecular Biology of the Cell

Are there any other prokaryotes besides bacteria?

Yes! Archaea and Bacteria are the two domains of prokaryotes. Relevant to our in class discussion, Algae are Eukaryotes, whereas cyanobacteria are bacteria, but confusingly are commonly called blue-green algae.

Why Uracil in RNA instead of Thymine?

Here is a link to one explanation: Uracil in RNA

and another: Uracil in RNA.

The short answer: Thymine takes more energy to make (and is made from Uracil) but has several advantages in DNA, where mutations cannot be tolerated. Urasil can base pair with other bases, including itself. Cytosine can degrade into a Uracil and therefore its best if all Uracil in DNA is treated as a error that needs to be fixed.