Which observation suggested to sutherland the involvement of a second messenger in epinephrine’s effect on liver cells?
a. enzymatic activity was proportional to the amount of calcium added to a cell-free extract.
b. receptor studies indicated that epinephrine was a ligand.
c. glycogen breakdown was observed only when epinephrine was administered to intact cells.
d. glycogen breakdown was observed when epinephrine and glycogen phosphorylase were combined.

Abnormal softening of a gland is known as

Which statements describe resources? one of the factors people use when deciding where they will live is the availability of resources. renewable resources have little value for people. resources are unevenly distributed throughout the world. energy is the world resource which has the highest use. the use of nonrenewable resources has decreased in recent history. the use of resources is evenly distributed throughout the world. the world's oil supply will last for the next forty years if its use continues as expected.

Wich organism obtains its energy from dead or decaying matter