Which motion of particles across a membrane requires energy?

In this experiment you were asked to present three possible mechanisms. describe those mechanisms here and include drawings of those mechanisms. how will the bromination of trans-cinnamic acid and trans-stilbene allow you to distinguish between the three possibilities? what would you expect to find in your data in each scenario?

Most of the fossils found in virginia are in the coastal plain, valley, ridge, and appalachian plateau regions, best suggesting that these geographic provinces a) were once covered by seawater. b) are the oldest parts of virginia. c) have a great deal of karst topography. d) have large amounts of sedimentary rock.

Which of these parts of the membrane large moecules pass through it ?