Protein or the physical region of the protein that participates in chemical catalysis. In solution proteins also undergo variation in structure through thermal vibration and the collision with other molecules. Proteins can be informally divided into three main classes, which correlate with typical tertiary structures: globular proteins, fibrous proteins, and membrane proteins. Almost all globular proteins are soluble and many are enzymes. Fibrous proteins are often structural, such as collagen, the major component of connective tissue, or keratin, the protein component of hair and nails. Membrane proteins often serve as receptors or provide channels for polar or charged molecules to pass
The Keg of Nails 2014. Cincinnati leads the series 30–22–1. The Keg of Nails The Keg of Nails is a traveling trophy continuously-awarded to the winner of the American college football rivalry game between the Cincinnati Bearcats and Louisville Cardinals. The rivalry has stretched over the span of four conferences from the Missouri Valley Conference, to the Metro Conference to Conference USA, and more recently in the Big East Conference, which in 2013 was renamed to the American Athletic Conference. It is believed to be the oldest rivalry for the Louisville football team and the second oldest for Cincinnati, only behind the annual game