11. Regulated metabolic pathways are

A. compartmentalized in eukaryotes
B. usually regulated at the first step
C. committed after the first step
D. all of these

12. When living organisms are cooled below some critical body temperature, the metabolic reactions within their cells cease to function properly. This malfunction occurs because

A. their enzymes lose the proper three-dimensional shape
B. enzyme active sites become permanently bound to substrates
C. the activation energy for the reaction is raised
D. there is the insufficient molecular motion for substrates to interact

13. Glycogen degradation requires the enzyme namely

A. glycogen phosphorylase and phosphoglucomutase
B. glycogen phosphorylase and glycogen-debranching enzyme
C. glycogen synthase and phosphorylase
D. none of the above

14. The hormones, glucagon and epinephrine, stimulate glycogen breakdown to G-6-P

A. only in the liver
B. using ATP as the phosphoryl donor
C. directly, by binding to glycogen phosphorylase
D. indirectly, by first stimulating adenylate cyclase to make cAMP

15. What is the cause of the genetic disease known as Galactosemia?

A. Deficiency in lactase
B. Absence of galactose 1-P uridyl transferase
C. Absence of lactose synthetase
D. Nonfunctioning of semnase