EVERYDAY SCIENCE

Detailed explanation-1: -Passive transport, most commonly by diffusion, occurs along a concentration gradient from high to low concentration. No energy is necessary for this mode of transport.

Detailed explanation-2: -Facilitated diffusion does not need any energy for the movement of molecules as they move from higher concentration to lower concentration gradient. This means they obey Fick’s law.

Detailed explanation-3: -Facilitated diffusion is a passive process: the solutes move down their concentration gradient and do not require the expenditure of cellular energy for this process. Carrier proteins and channel proteins allow for the diffusion of molecules across the cell membrane.

Detailed explanation-4: -Simple diffusion does not require energy: facilitated diffusion requires a source of ATP. B. Simple diffusion can only move material in the direction of a concentration gradient; facilitated diffusion moves materials with and against a concentration gradient.

Detailed explanation-5: -Facilitated transport (or facilitated diffusion) is defined as a mediated transport not requiring energy expenditure, as exemplified by placental glucose transfer, which is mediated by facilitative glucose transporters expressed in the syncytiotrophoblast MVM and BM.