Lecture 8: Cell Walls & Their Role in Regulating Plant Cell Shape

These flashcards cover key concepts regarding cell walls and their role in plant cell structure and function.

The annual production of plant cell walls is estimated to be __ billion tons/year.

150–170

Cellulose is a __ that forms the major component of plant cell walls.

glucose polymer

Extensins are proteins involved in __ of the cell wall, which increases its strength.

cross-linking

The primary plant cell wall provides __ strength to plant cells.

structural

The __ is a large, membrane-bound organelle in plant cells that helps regulate osmotic pressure.

vacuole

Cell walls prevent excessive __ uptake in plant cells.

water

Pectin and hemicellulose are transported to the cell surface by __.

exocytosis

Plasmodesmata serve as intercellular connections that enable __ communication between plant cells.

cell-to-cell

The secondary cell wall is __ and stronger than the primary cell wall.

thicker

The process of water movement into a cell by osmosis occurs from a high concentration to a low concentration.

water; water

Lignin is a complex polymer that confers __ and rigidity to the secondary cell wall.

strength

Microfibrils in the secondary cell wall have different __ that contribute to its strength.

orientations

The protoplast pushes against the cell wall to maintain __.

plant structure

Wilting occurs when the protoplast is not pushing against the __.

cell wall

The __ layer is composed of pectin and cellulose and connects adjacent plant cells.

middle lamella

Cellulose-producing rosettes are located in the __ membrane.

plasma

The cell wall influences cell __, providing support and preventing over-expansion.

morphology

In plant cells, turgor pressure is created as the protoplast expands and pushes against the __.

cell wall

The primary plant cell wall synthesis involves three coordinated steps: cellulose, hemicellulose and pectin synthesis, and __ of extensins.

exocytosis

Osmosis is the diffusion of water across a __ permeable membrane.

selectively