Lect 8 - cell walls & their role in regulating plant cell shape

Flashcards about plant cell walls, their structure, components, and functions in regulating plant cell shape.

What are the two main components of a plant cell?

The cell wall and the protoplast.

What is the most abundant organic macromolecule on earth and a major component of the cell wall?

Cellulose.

Name the two phases present in the cell wall structure.

Crystalline phase (microfibrils) and non-crystalline matrix.

What are cellulose rosettes and where are they located?

Protein complexes located in the plasma membrane that synthesise cellulose microfibrils.

What is the function of the middle lamella?

Acts as a glue holding neighbouring plant cells together.

What are the main functions of the cell wall?

Regulating cell shape and structural support.

What happens when the protoplast doesn’t push against the cell wall?

The plant wilts.

What limits the volume of water taken up by a plant cell?

Pressure on cell wall (turgor pressure) limits the volume of water taken up.

What is the composition of secondary cell walls?

More cellulose, less pectin, and lignin.

What is the function of plasmodesmata?

Intercellular connections that enable cell communication.

What is the protoplast?

The entire contents of the cell enclosed by the plasma membrane.

What is the role of vacuoles in regulating water uptake?

They contain a high concentration of solutes, causing water to move in via osmosis and limiting further water uptake.

What is Lignin?

A complex polymer that provides strength and rigidity and excludes water in the secondary cell wall.