2 The Particle Model of Matter In order to survive and function properly cells need to move gases, ions, nutrients, and waste material across their selectively permeable membrane.
3 Understanding how particles move Particle ModelAll matter is made of particlesThe particles of matter are constantly moving or vibratingthe particles of matter are attracted to one anotherparticles have spaces between themParticle Movement is described by Brownian motion: the random movement of microscopic particles suspended in a fluid. Applet
15 Endocytosis and Exocytosis movement of larger molecules in and out of the cell with transport vesicles. (animation)
16 Endocytosis:Bringing substances into the cell by wrapping them in part of the cell membraneEx. nutrientsPhagocytosis: Bringing in a large particle (animation)Pinocytosis: Brining in many small particlesReceptor Mediated Endocytosis: process is triggered by a receptor on the surface of the membrane