Give a brief account of enzymes as biological catalysts

enzymes speed up a reaction but aren't used up during the reaction

Explanation:

a catalyst speeds up a reaction by lowering the amount of energy it takes for the reaction to occur enzymes are described as biological catalysts because they speed up the reaction without being used in the reaction

what statement best describes the difference between the sympathetic and parasympathetic nervous systems?

the sympathetic nervous system prepares the body for intense physical activity and is often referred to as the fight-or-flight response. the parasympathetic nervous system has almost the exact opposite effect and relaxes the body and inhibits or slows many high energy functions.