Question: The TCA cycle enzyme fumarase catalyzes the conversion of fumarate to form malate. The turnover number for this enzyme is 800/sec. The Km of fumarase for its substrate is 5uM. A) In an experiment using 2 nanomol/L of fumarase, what is the Vmax? The cellular concentration of fumarate is 47.5 uM. What is the reaction velocity when [fumarate ] is 47.5 uM? What is the catalytic efficiency of fumarase? Does fumarase approach catalytic perfection. Need Assignment Help?