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.
CARDIOVASCULAR EFFECTS, BLOOD PRESSURE, AND KIDNEY DISEASE. There is some evidence that caffeine can cause momentary increases in the blood pressure (up to 10 mm Hg), especially in people who are not habitual coffee drinkers. However, this effect is enhanced in the elderly, and people who have underlying hypertension.