cell membrane - the thin layer of protein and fat
that surrounds the amoeba; it allows some substances to pass into the cell, and blocks other substances. contractile vacuole - a cavity within the amoeba that excretes excess water and waste; the waste is brought to the cell membrane and is then eliminated from the amoeba. cytoplasm - a jelly-like material that fills most of the cell; the organelles (like the nucleus) are surrounded by cytoplasm. food vacuole - a cavity within the amoeba in which food is digested (broken down in order to be absorbed by the amoeba). food being engulfed by pseudopods - the amoeba "eats" by surrounding bits of food with pseudopods that form around the food; the amoeba then incorporates the food into the cell, forming a food vacuole. nucleus - the major organelle of the amoeba, located centrally; it controls reproduction (it contains the chromosomes) and many other important functions (including eating and growth). pseudopods - temporary "feet" that the amoeba uses to move around and to engulf food.