Many enzymes consist of a protein and a non-protein (called the cofactor). The proteins in enzymes are usually globular. The intra- and intermolecular bonds that hold proteins in their secondary and tertiary structures are disrupted by changes in temperature and pH. This affects shapes and so the catalytic activity of an enzyme is pH and temperature sensitive.
Everyday in the U.S. millions of cars and trucks idle needlessly, sometimes for hours. You may not be able to avoid keeping your engine running when youâre stopped at a traffic signal or stuck in slow-moving traffic. But other times idling is unnecessary. An idling car can release as much pollution as a moving car.
Car Only Overheats When Driving If you have recently been stuck on the side of the road in soaring temperatures with an overheating car, you may be wondering why your car only overheats when driving. You may have let it idle for 10 minutes in the driveway before you left and yet here you are a few miles away with a steaming vehicle.