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.
Coffee containing caffeine can cause insomnia, nervousness and restlessness, stomach upset, nausea and vomiting, increased heart and breathing rate, and other side effects. Consuming large amounts of coffee might also cause headache, anxiety, agitation, ringing in the ears, and irregular heartbeats. Drinking unfiltered coffee can increase total cholesterol, low-density lipoprotein (LDL), and levels of another type of blood fat called triglycerides. This might increase the risk of developing heart disease.