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.
If you do need to idle your vehicle, remain in the driver's seat at all times. 5. You can damage your classic car. If you own an older vehicle, with an old-fashioned carburetor instead of a fuel-injection engine, you may need to give it a minute or two of idling, to let the oil thin out, but no more than that.