Study Sheet for Cells Test Scientific Method: define a problem, form a hypothesis, gather experimental data, form a conclusion Robert Hooke (1665)-looked at cork under a microscope and called what he saw CELLS! Words to Know: Cell wall: A tough outer covering that surrounds the plasma membrane of bacteria and plant cells. Cilia: Short projections that cover the surface of some cells and provide for movement. Cytoplasm: The semi fluid substance of a cell containing organelles and enclosed by the cell membrane. Cytoskeleton: The network of filaments that provide structure and movement of a cell. DNA (deoxyribonucleic acid): The genetic material in the nucleus of cells that contains information for an organism's development. Endoplasmic reticulum: The network of membranes that extends throughout the cell and is involved in protein synthesis and lipid metabolism (There is smooth and rough ER; rough has ribosome on outside) Eukaryote: A cell that contains a distinct nucleus and organelles. YOU= Eukaryote! Flagellum: A whip like structure that provides for movement in some cells. (Like a tail) Golgi body: Organelle that sorts, modifies, and packages molecules (Like a post office) Membrane: A thin, flexible layer of plant or animal tissue that covers, lines, separates or holds together, or connects parts of an organism. Mitochondrion: The power-house of the cell that is responsible for turning food into energy. Nuclear envelope: The double membrane that surrounds the nucleus. Nucleolus: The darker region inside the nucleus where ribosomal subunits are made. Nucleus: The control center of a cell that contains the DNA. Organelle: A membrane-bounded cellular "organ" that performs a specific set of functions within a eukaryotic cell. (Prokaryotes have NO membrane-bound organelles) Pili: Short projections that assist bacteria in attaching to tissues. (Hair-like legs) Plasma membrane: The membrane of a cell. Prokaryote: A cell without a true nucleus. (Pro means NO…like no nucleus) Protein: Large molecules that are essential to the structure and functioning of all living cells. Ribosome: A protein that is made in the Endoplasmic Reticulum and appears all over the cell. Vacuole: A space-filling organelle of plant cells. (Animals have small vacuoles/Plants have one big vacuole) Vesicle: A membrane-bound sphere that contains a variety of substances in cells. (Like a package)