What is an active site and what is its relationship to an enzyme? an active site in an enzyme is the area that breaks the bond in its substrate. E.g. a maltose molecule's glycocide bond is broken by the active site in a maltase enzyme.
The caffeine in a cup of coffee might help your small blood vessels work better. Credit: Â© jogyx / Fotolia. The caffeine in a cup of coffee might help your small blood vessels work better, according to research presented at the American Heart Association's Scientific Sessions 2013.
Heart Disease. By Richard N. Fogoros, MD - Reviewed by a board-certified physician. In the past, coffee was generally regarded as being detrimental to heart health. Coffee was said to increase blood pressure, increase cholesterol levels, and increase the risk of heart attack and cardiac arrhythmias. However, more recent and more careful studies have suggested that coffee probably does not increase the risk of heart disease; and in some cases may even be beneficial.