9th grade Biology Cell

prokaryote

a cell without a nucleus

eukaryote

An organism whose cells have a nucleus

cell

the basic unit of structure and function in an organism

unicellular

made of a single cell

multicellular

organisms composed of many cells

nucleus

control center if the cell that contains coded directions for making protein and for cell division

Plasma membrane (cell membrane)

a thin flexible boundary of protein and fat that controls the movement of substances in and out of the cell

vacuole

fluid-filled vesicle that temporarily stores materials (water and food)

endoplasmic reticulum (ER)

a highly folded membrane that is the site of protein sythesis (smooth-without ribosomes, rough-with ribosomes

ribosomes

small structures on the ER that manufacture proteins

mitochondria

a membrane bound organelle that makes energy for the rest of the cell; the powerhouse of the cell

golgi apparatus (golgi bodies)

flattened stacks of membranes that make like proteins and package them for distribution outside the cell

chloroplasts

a double-membrane barrier containing chlorophyll in plant cells

cell wall

inflexible barrier surrounding and protecting the plant cell

centrioles

cylinder-shaped structures that occur in pairs and are important in cell division

lysosome

a vesicle containing digestive enzymes for the breakdown of excess substances

vesicle

sac formed when cell membranes surrounds food or large molecules

microtubules (cytoskeleton)

hollow rods of protein that make a framework and give the cell its shape

cytoplasm

a semi-liquid fluid that fills the cell; it is made of mostly water and important molecules necessary for cell survival

flagella

projections that aid in locomotion and feeding

cilia

projections from cell surfaces that aid in locomotion and feeding; also used to sweep substances along surfaces