Cell Survival

A collage of protein and virus crystals, many of which were grown on the U.S. Space Shuttle or Russian Space Station, Mir. The crystals include the proteins canavalin; mouse monoclonal antibody; a sweet protein, thaumatin; and a fungal protease. Viruses are represented here by crystals of turnip yellow mosaic virus and satellite tobacco mosaic virus.

The crystals are photographed under polarized light (thus causing the colors) and range in size from a few hundred microns in edge length up to more than a millimeter. All the crystals are grown from aqueous solutions and are useful for X-ray diffraction analysis. Credit: Dr. Alex McPherson, University of California, Irvine.

Enzymes, protein catalysts, are integral to the survival of the cell by speeding up biological reactions.

Today the students reviewed thermochemistry and the basics behind reactions, and then explored the concepts behind kinetics and why reactions occur. The students expanded upon this knowledge through the lens of biochemistry with a discussion of enzymes, substrates and cofactors. Through a hands-on experiment done together remotely, the students observed how addition of catalase (via yeast) sped up the decomposition of hydrogen peroxide into hydrogen and oxygen gas. We will continue to discuss the mechanism of yeast catalase and how this leads to a speedup in the reaction.