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.
After the car warms up for several minutes and the idle speed decreases, the car RPM drops and the engine quits. I keep the engine going by pushing down on the gas pedal and maintaining the engine at a higher RPM. If I drive it and come to a stop, the engine will quit.994 Toyota Land Cruiser. Starts up and idles fine initially. After initial warm up period, it won't idle and engine quits. After running for 10 minutes, it idles fine. What needs to be repaired to fix this problem.