The cell wall Flashcards
cell wall
a freely permeable wall around plant cells, made mainly of cellulose
suberin
a waterproof chemical that impregnates cellulose cell walls in cork tissues and makes them impermeable
lignin
a chemical that impregnates cellulose cell walls in wood and makes them impermeable
middle lamella
the first layer of the plant cell wall to be formed when a plant cell divides, made mainly of calcium pectate (pectin) that binds the layers of cellulose together
pectin
a polysaccharide that holds cell walls of neighboring plant cells together and is part of the structure of the primary cell wall
primary cell walls
the very first flexible plant cell walls to form, with all the cellulose microfibrils orientated in a similar direction
secondary cell wall
the older plant cell wall in which the cellulose microfibrils have built up at different angles to each other making the cell wall more rigid
hemicelluloses
`polysaccharides containing many different sugar monomers
plant fibres
long cells with cellulose cell walls that have been heavily lignified so they are rigid and very strong
composite material
`a material made of two or more materials which combined together make a composite with different properties from either of the constituent materials
turgid
swollen
flaccid
floppy, soft
plasmodesmata
cytoplasmic bridges between plant cells that allow communication between the cells
symplast
all of the material (cytoplasm, vacuole etc.) contained within the surface membrane of a plant cell
pits
thin areas of cell wall in plant cells with secondary thickening, where plasmodesmata maintain contact with adjacent cells; in xylem vessels, where the cells are dead, the become simple holes through which water moves out into the surrounding cells
