cell differentiation
process by which a cell changes to become specialized to perform a certain function
cell wall
rigid carbohydrate structure that provides overall support and protection for the cell. It is found in some, but not all, cells.
cellulose microfibril
bundle of polysaccharide chains that contributes to plant cell wall structure
collagen
protein that makes up the bulk of the extracellular matrix in animal tissues
desmosome
cell junction that connects cells via specialized proteins and helps maintain tissue strength
embryonic stem cell (ES cell)
undifferentiated cell that can give rise to more differentiated cells in a developing animal embryo
epithelium (plural, epithelia)
tissue made of a sheet of cells that covers the surface of the body as well as the outside and inside of many internal organs
extracellular matrix
molecular framework secreted by cells that supports them structurally and biochemically
fibroblast
cell that makes the extracellular matrix, including collagen
fibronectin
extracellular protein that attaches cell membrane proteins to collagen
gap junction
structure that connects adjacent cells via protein channels, allowing the direct movement of small molecules and ions from the cytoplasm of one cell to the cytoplasm of the next cell
glycosaminoglycan (GAG)
polysaccharide chain of repeating disaccharides, usually linked to a core protein, that forms part of the extracellular matrix
hemidesmosome
junction complex that binds epithelial cells to the basal lamina (border between epithelium and connective tissue)
induced pluripotent stem cell (iPS)
adult cell that has been transformed into a pluripotent stem cell (able to give rise to any other body cell type) through the application of specific stimuli
inner cell mass
collection of stem cells in an early embryo that will give rise to the different parts of the developed animal
multipotent stem cell
stem cell that can give rise to a limited number of other body cell types
plasmodesma (plural, plasmodesmata)
small channel connecting the cytoplasm of adjacent plant cells through which molecules pass
pluripotent stem cell
stem cell that can give rise to many different cell types
reproductive cloning
formation of an animal that is a genetic copy of its genetic donor by transplanting the nucleus of a somatic cell into an egg that has had its nucleus removed
therapeutic cloning
transfer of the nucleus of a somatic cell into an egg cell that has had its nucleus removed to form an embryo, from which embryonic stem cells can be derived
tight junction
protein junction that connects the plasma membranes of two cells, preventing molecules from passing through the space between cells
tissue
integrated, cooperative assembly of cells working together
totipotent stem cell
stem cell that is able to give rise to an entire organism from a single cell