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clearscience:

The FDA recently chose not to impose new regulations on bisphenol-A, which has sometimes been used in food packaging. Let’s look at what bisphenol-A is, how it’s used to make materials, and why it can be harmful if people ingest it. Bisphenol-A is shown above. Like many chemicals, its name can tell you how it looks:

Bis (two)

phenol (the red circle on the left: a benzene ring attached to an OH)

A (acetone, where the 3 carbons in the middle come from)

So bisphenol-A is made by reacting 2 parts phenol with one part acetone. These are all common chemicals that don’t cost a lot, so bisphenol-A isn’t too expensive to make.

What makes it useful is the OH on each side. This makes it like a building block that can attach to something on each side. In other words, it can do something in two places or is bi-functional.

Building blocks that can attach on both sides can be used to make long chains. And polycarbonate (sometimes called Lexan) is a long molecular chain mostly made of bisphenol-A. Many things, like jet canopies, are made of polycarbonate. Unfortunately it’s also been used in food containers. We’ll talk about that next.

1 week ago / 28 notes / Source: clearscience

stressface:

One plant yields 3 clues to biofuel crops

The analysis of gene activity by researchers at Iowa State University and determination of protein structures by scientists at the Salk Institute for Biological Sciences independently identified three related proteins that appear to be involved in fatty-acid metabolism. The researchers used thale cress (Arabidopsis thaliana) as the model plant.

The research groups then joined forces to test this hypothesis, demonstrating a role of these proteins in regulating the amounts and types of fatty acids accumulated in plants.

The researchers also showed that the action of the proteins is very sensitive to temperature and that this feature may play an important role in how plants mitigate temperature stress using fatty acids.

The discovery is published online in the journal Nature.

“This work has major implications for modulating the fatty-acid profiles in plants, which is terribly important, not only to sustainable food production and nutrition but now also to biorenewable chemicals and fuels,” says corresponding author Joseph Noel, a professor and director of the Jack H. Skirball Center for Chemical Biology and Proteomics at the Salk Institute and an investigator with the Howard Hughes Medical Institute.

In this photo: The blue areas in this thale cress plant indicate where the fatty-acid-binding protein one gene is expressed and also correspond to regions where high fatty acids would be synthesized by the plant. (Credit: Eve Syrkin Wurtele and Micheline Ngaki)

Read more here.