SCItations

They say imitation is the sincerest form of flattery. The field of optogenetics has taken that motto to heart and paid photosynthetic algae an immense complement. It’s actually very common for science and engineering technology to take a hint from nature, but in this case that hint was actually entire gene sequences. Channelrhodopsins are a group of proteins found in some photosynthetic algae which directly regulate the flow of ions through membranes. I’ve talked about channel proteins before and how their activity can be modulated by either chemical or electrical signals, but these channelrhodopsins are special because they are activated by light. The discovery of the genes that code for these proteins and the genetic engineering that has introduced these genes into mammalian cells has spurred research in the area called optogenetics . Perhaps most famously, optogenetics has been applied to neuroscience with the transfection of neurons with the channelrhodopsin gene. A

Frigid temperatures in Arkansas this weekend have inspired an icy topic.   If you’ve ever wondered why your lettuce wilts when it accidentally freezes in the refrigerator, or your basil dies after the first frost then this post is for you.  Contrary to what I believed and maybe what some of you do to, plant cells themselves rarely freeze. The water in between cells freezes much more readily than the cells themselves; this is the start of the plant’s problems.  Dehydration is the most common culprit for cell death at cold temperatures. It seems counter intuitive that dehydration would occur as a result of freezing water , but it makes sense when you begin to think like a plant cell. All living cells exist in a state of equilibrium with their surroundings. Ions, gases, small molecules and water are constantly moving around the plant, going in and out of cells as needed. The concentrations of these species inside and outside of the cell are carefully regulated by the plant. S

As we have witnessed all too recently, chemical warfare is a very tangible concern for many people of the world. The latest large scale attack occurred in Syria only a few months ago with the use of Sarin gas. The news from Syria makes it all the more urgent that scientists find ways to combat the use of chemical weapons. A group of engineers at UC San Diego have done just that using a new kind of structure called “micromachines”. Many chemical weapon agents used in warfare belong to a class of chemicals broadly labeled “organophosphates”. This label is given to molecules that have a generically organic part and a phosphate part. Here is the molecule sarin, with its organic and phosphate parts highlighted: Nerve gasses like sarin are dangerous because of the way the molecules interact with our nervous system. This interaction is highly dependent on the shape, or conformation of the molecule. That is, if we could somehow break up the atoms in the sarin molecule, they w

There is big news this week from the FDA who has banned the use of trans-fat in the entire food industry. I thought this would be an appropriate time to discuss the different types of fats we see on our food labels, and why the heck trans-fat got the snub. Fatty acids that you and I eat have a couple defining chemical characteristics. One side of the molecule is the fatty part and one side of the molecule is the acid part – pretty convenient. Here is a representation of a fatty acid molecule:    The fatty acid chain as it is called is made up of a long string of carbon and hydrogen atoms. The type of bonds between the carbon atoms determines whether a fatty acid is saturated or unsaturated. The fatty acid above is saturated because the fatty acid chain contains only single bonds between carbon atoms. Another way to think about saturated and unsaturated fats is to talk about the number of hydrogen atoms bonded to the carbon chain. Saturated fats have the maximum number of h