Assessing the metabolic consequences of life without enzymesthe incredible catalytic power of enzymes can perhaps best be appreciated by imagining how challenging life would bewithout/ust one of the thousands of enzymes in the human body. for example, consider life without fructose-1,6-bisphospha tase, an enzyme in the gluconeogenesls pathway in liver and kidneys (see chapter22), which producenew glucose from the food we eat: fructose-1,6-blsphosphate e h20 -» fructose-s-f + pithe human brain requires glucose as its only energy source, and the typical brain consumes about 120 g (or 480 calories)of glucose dally. ordinarily, two pieces of sausage pizza could provide more than enough potential glucose to feed thebrain fora day. according to a national fast-food chain, two pieces of sausage pkza provide 1340 calories, 48% of whichis from fat. fa ts cannot be converted to glucose in gluconeogenesls, so that leaves 697 calories poten tially available forglucose synthesis. the first»order rate constant for the hydrolysis of fructose-1,6-blsphosphate in the absence of enzymeis 2‘10-20/sec. calculate how long it would take to provide enough glucose for one day of brain activity from two piecesof sausage pizza without the enzyme.