Cartoon about strong acids and bases

Animation abou mitosis

One more animation about mitosis...

http://www.mediafire.com/?qcv0j1uuhjdvxz1

Video about functional groups (2)

Metabolic map on the synthesis of methionine and threonine

Scientific cartoon (3)

Carboxyl group

The carboxyl group is composed of two oxygen atoms bound to a carbon, one by a double bond and the other through a single bond. The latter is also covalently bonded to a hydrogen atom (R-COOH). Put simply, it can be seen as a functional group comprising a carbonyl group and a hydroxyl group.

The carboxyl group is the main acidic group in organic chemistry, and therefore can lose an H⁺, resulting in an anionic carboxylate group (R-COO^-). Carboxylate ions are stabilized by electronic resonance, which allows the carboxyl group to present a significant acidic behavior. Carboxyl groups are highly polar and can act as H donors and acceptors in hydrogen bonds.

In biochemistry, the carboxyl groups are sometimes removed from biomolecules in the so-called decarboxylation reactions (they are released in the form of CO₂).
The presence of carboxyl groups in the molecules can be detected by infrared spectroscopy, showing a characteristic vibration between 1680 and 1725 cm^-1. Alternatively, it can be identified by nuclear magnetic resonance, appearing in the region of 10-13 ppm.

Famous sentence (2)

“People are DNA’s way of making more DNA.” - Edward O. Wilson.

Tattoos - atom (4)