chapter 4 matching 9
ECM
Layers of firm material scattered onto the primary cell walls inner surface that strengthen the wall and maintain its shape
tight junctions
Seal abbutting cells that lone the piter surfaces and internal cavities of animals so no fluids can pass between them
cuticle
a protective body covering made of cell secretions
middle lamella
a sticky layer in between the primary walls of adjoining cells
lignin
a strong waterproof component of the secondary wallsof older stems and roots
adhering junctions
anchor cells to each other and to the extracellular matrix
plasmadesmata
cytoplasmic channels that cross the cell walls and join neighboring plant cells
secondary wall
nonliving mixture of fibrous proteins and polysaccharides surrounding the cells that secrete it
gap junctions
open channels that connect the cytoplasm of neighboring animal cells
pectin
substance a young plant cell first secretes onto the outer surface of its plasma membrane
cellulose
the main constituent of a plants primary cell wall
primary wall
thin, pliable structure made of polysaccharides that allows plant cells to grow and enlarge