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.
Also, if you idle the engine excessively, you must visually inspect your oil, because you will need to change it more than every 3,000 miles. The answer depends on the fuel efficiency of your car, Whether the car is in Neutral, or drive, and the appliances (AC, radio, lights, etc) you have on. As an example, my car gets 27 MPG on the freeway going about 60 MPH. My gas tank is 18 gallons. This means that on the freeway, my car would run for about 8.1 hours.