Chapter 11: Cell-Cell Interactions

Symplast

________ is a continuous network of cytoplasm connected by plasmodesmata.

Cadherins

________ are the linking proteins in desmosomes.

ground substance

The ________ that surrounds collagen and other fibrous components of the ECM contains highly glycosylated, gel forming proteins called proteoglycans.

Expansins

________ disrupt the hydrogen bonds that crosslink microfibrils to other polymers in the wall, loosening the structure and allowing the microfibrils to slide past one another.

Hormones

________ are information- carrying molecules that are secreted by plant and animal cells into bodily fluids and act on distant target cells.

Desmosome

________ is a strong cell- cell attachment particularly common in animal epithelial cells and certain muscle cells.

immune response

An antibody is a protein produced by a(n) ________ that binds specifically to a unique type of molecule, often another protein.

gelatinous polysaccharides

The spaces between microfibrils are filled with ________ such as pectins- the molecules that are used to thicken jams and jellies.

signal receptor

A(n) ________ is a protein that changes its shape and activity after binding to a signaling molecule.

tissue

A(n) ________ consists of similar cells that function as a unit.

Materials

________ and structures that bind cells together are particularly important in epithelial- tissues that form external and internal surfaces.

Apoplast

________ is the region outside the plasma membrane.

tight junction

A(n) ________ is a cell- cell attachment composed of specialized proteins in the plasma membranes of adjacent animal cells.

eukaryotic microbes

The use of signaling pathways to respond to population density in prokaryotic and ________ is referred to as quorum sensing.

basis of multicellularity

Direct physical connections between cells are the ________.

Membrane proteins

________ called integrins bind to extracellular cross- linking proteins, including laminins, which in turn bind to other components of the ECM.

Second messenger

________ is a small, nonprotein signaling molecule or ion that elicits an intracellular response to the first messenger.

Protein kinases

________ are enzymes that activate or inactivate other proteins by adding a phosphate group to them.

Signal transduction

________ is the conversion of a signal from one form to another.

peripheral membrane proteins

Many signal receptors span the plasma membrane and are closely associated with ________ inside the cell called G proteins.