Biology 7.1 + 7.2 Vocabulary

Cell

Basic unit of all forms of life

Cell Theory

Fundamental concept of biology that states that all living things are composed of cells; that cells are the basic units of structure and function in living things; and that new cells are produced from existing cells

Cell Membrane

Thin, flexible barrier that surrounds all cells; regulates what enters and leaves the cell

Nucleus

In cells, structure that contains the cell's genetic material in the form of DNA.

Eukaryote

Organism whose cells contain a nucleus.

Prokaryote

Unicellular organism that lacks a nucleus.

Cytoplasm

In eukaryotic cells, all cellular contents outside the nucleus; In prokaryotic cells, all of the cells' contents

Organelle

Specialized structure that performs important cellular functions within a cell.

Vacuole

Cell organelle that stores materials such as water, salts, proteins, and carbohydrates.

Lysosome

Cell organelle that breaks down lipids, carbohydrates and proteins into small molecules that can be used by the rest of the cell.

Cytoskeleton

Network of protein filaments in a eukaryotic cell that gives the cell its shape and internal organization and is involved in movement.

Centriole

Structure in an animal cell that helps to organize cell division.

Ribosome

Cell organelle consisting of RNA and protein found throughout the cytoplasm in a cell; the site of protein synthesis.

Endoplasmic Reticulum

Internal membrane system found in eukaryotic cells; place where lipid components of the cell membrane are assembled.

Golgi Apparatus

Organelle in cells that magnifies, sorts, and packages proteins and other materials from the endoplasmic reticulum for storage in the cell or release outside the cell.

Chloroplast

Organelle found in cells of plants and some other organisms that captures the energy from sunlight and converts it into chemical energy.

Mitochondrion

Cell organelle that converts the chemical energy stored in food into compounds that are more convenient for the cell to use.

Cell Wall

Strong, supporting layer around the cell membrane in some cells.

Lipid Bilayer

Flexible double-layered sheet that makes up the cell membrane and forms a barrier between the cell and its surroundings.

Selectively Permeable

Property of biological membranes that allows some substances to pass across it while others cannot; also called semipermeable membrane.