process in which cells become specialized in structure and function
the basic structural and functional unit of all organisms
the aqueous part of the cytoplasm within which various particles and organelles are suspended
thin, flexible barrier around a cell; regulates what enters and leaves the cell
A two-layered arrangement of phosphate and lipid molecules that form a cell membrane, the hydrophobic lipid ends facing inward and the hydrophilic phosphate ends facing outward.
a network of fibers that holds the cell together, helps the cell to keep its shape, and aids in movement
a cell organelle composed of RNA and protein; the site of protein synthesis
a system of membranes that is found in a cell's cytoplasm and that assists in the production, processing, and transport of proteins and in the production of lipids
membranous sacs that very in size and contents; form when a portion of the cell membrane folds inward and pinches off
a stack of flattened, sacs called cisternae, that refines, packages, and delivers proteins synthesized on the rough ER
elongated, fluid-filled sacs, that contains a small amount of DNA that encodes information for making a few types of proteins; convert energy in food molecules to energy in the form of ATP, adenosine triphosphate, that the cell can use to carry out its functions (cellular respiration)
membrane-bound sac containing digestive enzymes that can break down proteins, nucleic acids, polysaccharides, and old worn out cell parts
A microbody containing enzymes that transfer hydrogen from various substrates to oxygen, producing and then degrading hydrogen peroxide; found mostly in liver and kidneys.
Structure present in the cytoplasm of animal cells, important during cell division; functions as a microtubule-organizing center.
The hair-like structures on the surface of epithelial (covering) cells, such as those of the bronchi, that provide upward movement of mucus cell secretions
long, thin, whip-like structures, with a core of microtubules, that enable some cells to move: found in sperm cells
a component of the cytoskeleton that is made from actin proteins
straight, hollow tubes of proteins that give rigidity, shape, and organization to a cell
double membrane that surrounds a cell nucleus
small holes in the nuclear envelope through which substances pass between the nucleus and the cytoplasm
a small, dense body in the nucleus where ribosomes are made, synthesized and partially assembled
granular material visible within the nucleus; consists of DNA tightly coiled around proteins
condensed threads of genetic material formed from chromatin as a cell prepares to divide
smooth endoplasmic reticulum
An endomembrane system where lipids are synthesized, calcium levels are regulated, and toxic substances are broken down.
a part of the cell containing DNA and RNA and responsible for growth and reproduction
the fluid portion of the cytoplasm