Structure & Function of the Plant Cell

By Kat Milner
Plant cells have thick, stiff walls.
Image by Flickr.com, courtesy of Umberto Salvagnin

Except for some single-celled organisms, such as bacteria and blue green algae, all living cells have a membrane-enclosed nucleus and internal structures called organelles. Most of these are common to both animals and plants. But plant cells have several specialized characteristics.

Cell Walls

Surrounding the plasma membrane, the cell wall is a complex structure that provides protection and rigidity, regulates plant growth, and provides a porous medium for distribution of water and nutrients.

Chloroplasts

Image by Flickr.com, courtesy of Sherrie Thai

Plastids store and synthesize metabolic materials. Chloroplasts convert light into chemical energy, a process called photosynthesis--exclusive to plants.

Vacuoles

A large central sac, the vacuole, stores nutrients, waste products and pigments. It also provides structural support for the plant; filled with water, a vacuole may occupy 80 percent or more of the cell and exert significant pressure against the cell wall.

Plasmodesmata

Small tubes called plasmodesmata penetrate cell walls and connect neighboring plant cells, to permit molecules to pass directly from one cell to another.

Endoplasmic Reticulum

The tubular network that connects the nucleus to everything else in the cell, the endoplasmic reticulum builds and moves compounds for use inside and outside the cell. It's common to both plants and animals; in plants, however, it also connects cell to cell through the plasmodesmata.

About the Author

Kat Milner has 35 years' experience in publishing and design, both for print and for Internet. Her background includes business, technical, and educational writing and editing; book editing (fiction and nonfiction); news editing; feature writing (celebrity interviews, music reviews); and publication design. She attended Mount Holyoke College in South Hadley, Massachusetts.