Active transport occurs when a solute moves "uphill" or against its electrochemical gradient because energy is required to concentrate a molecule in an area. ... The plasma membrane is impermeable to large or charged molecules. Diffusion is the simplest type of passive transport and requires no proteins to occur. read more
They provide transport proteins with the energy needed to pump molecules against their concentration gradients. Efflux pumps can be used to pump antibiotics out of a cell once they enter to protect the cell. read more
They provide transport proteins w/the energy needed to pump molecules against their concentration gradients Efflux pumps can be used to pump antibiotics out of a cell once they enter to protect the cell. read more