Cells and Their Environment Cells and Their Environment

Cells and Their Environment

Cells and Their Environment How do cells move materials in and out? Cells use passive and active transport Passive transport - The movement of molecules without expending energy (osmosis, diffusion) Active transport - The movement of molecules using the energy from ATP (endocytosis, exocytosis, molecular pumps)

Cells and Their Environment Diffusion - The movement of a molecule from a high concentration to a low concentration; needs no energy Perfume from a bottle

Cells and Their Environment Osmosis - A type of passive transport; involves the movement of just water from high to low concentration; needs no energy Why do slugs shrivel up when exposed to salt?

Cells and Their Environment Hypertonic - High solute outside the cell, low inside, water moves OUT Hypotonic - Low solute outside the cell, high inside, water moves IN Isotonic - Identical solute outside and inside the cell, NO net water movement

Cells and Their Environment Endocytosis - The movement of materials into a cell; requires ATP (energy) There are two types of endocytosis: Phagocytosis - The intake of larger particles (bacteria or even entire cells) Pinocytosis - The intake of small dissolved molecules (vitamins or minerals for example)

Cells and Their Environment Visuals of phagocytosis: Animation of phagocytosis

Cells and Their Environment Visuals of pinocytosis: Animation of pinocytosis

Cells and Their Environment Exocytosis - The movement of materials out of a cell; requires ATP (energy) Animation of exocytosis

Cells and Their Environment Facilitated diffusion - The pumping of molecules into or out of a cell from low to high concentration; works in the OPPOSITE direction as regular diffusion and requires energy (example: a molecular pump like the sodium potassium pump) Animation of sodium-potassium pump