In 1953, Stanley Miller and Harold Urey built a model of Earth's early atmosphere by mixing gases that were thought to have been there. They exposed the gases to an electric current to simulate lightning. The liquid that condensed during the experiment contained amino acids.

What was the significance of their results?
A.
Miller and Urey showed that all life evolved from a single common ancestor.
B.
Miller and Urey showed that lightning was necessary for life to form on Earth.
C.
Miller and Urey showed that inorganic compounds could combine to form the building blocks of living cells.
D.
Miller and Urey showed that spontaneous generation was possible.

a

explanation:

answer; both surfaces of the membrane are nonpermeable

it provides an alternative energy pathway for the reaction to proceed.

a catalyst is a substance that speeds up the rate of a chemical reaction but is not consumed during the course of the reaction.

catalysts increase the rate of reaction without being used up. they do this by lowering the activation energy needed. with a catalyst, more collisions result in a reaction, so the rate of reaction increases. different reactions need different catalysts.

a catalyst works by providing an alternative reaction pathway to the reaction product. the rate of the reaction is increased as this alternative route has a lower activation energy than the reaction route not mediated by the catalyst.