CELS191 Lecture 8: Cell Walls

Flashcards covering key vocabulary and concepts from the Cell Walls & Their Role in Regulating Plant Cell Shape lecture.

Cellulose

Most abundant organic macromolecule on Earth, a glucose polymer that forms highly ordered, long, ribbon-like structures.

Cellulose Microfibrils

Strong, highly organised structures forming a major component of both primary and secondary cell walls.

Hemicellulose

A heterogeneous group of polysaccharides that forms a rigid structure.

Pectin

Branched, negatively charged polysaccharides that bind water and have gel-like properties.

Extensin

A protein in the cell wall where extensin cross-linking of pectin and cellulose dehydrates the cell wall, reduces extensibility and increases strength

Exocytosis

A process that transports material out of the cell or delivers it to the cell surface.

Cytoskeleton

A network of microtubules and microfilaments that extends throughout the cytoplasm, maintaining the position of organelles and providing structural support.

Cell Wall Functions

Influences cell morphology, provides structural support, and prevents excessive water uptake.

Vacuole

An organelle surrounded by a single membrane that is highly selective, controlling much of what enters and leaves.

Osmosis

Diffusion of water across a selectively permeable membrane from high water (low solute) concentration to low water (high solute) concentration.

Turgor Pressure

Pressure from the cell wall that limits the volume of water that can be taken up.

Secondary Cell Wall

Thicker and stronger than primary cell walls that provide more structural support.

Lignin

A complex polymer that confers strength and rigidity to the secondary cell wall and acts to exclude water.

Plasmodesmata

Intercellular connections that enable cell to cell communication.