From Seed to Seed:
Plant Science for K-8 Educators

B. Plant Cells

The typical plant cell

A typical plant cell consists of a relatively rigid cell wall lined with a cell membrane. The cell wall determines the final size and shape of the cell and performs several functions that are essential to the cell. Within the cell membrane lie the nucleus and other structures suspended in a liquid matrix called the cytoplasm. This diagram represents a typical plant cell, such as you might find in a leaf. However, plant cells vary depending on their function. For example, root cells do not contain chloroplasts.

The nucleus is one of the larger structures in the cell. It has two functions:

• It controls the ongoing activities of the cell-serving as the "Mission Control."
• It contains the cell's chromosomes, which store the cell's genetic information, and passes this information on to the daughter cells during cell division.

Other important plant cell structures include:

• Vacuoles-filled with cell sap, a liquid (mostly water) containing various salts and sugars; these help regulate the water balance in cells.
• Plastids-contain various pigments and other compounds. Plastids containing the green pigment chlorophyll are called chloroplasts.
• Mitochondria-sites of cellular respiration and the production of energy used during cell functions.
• Ribosomes-the sites where proteins are synthesized.
• Golgi bodies-a "packing and shipping" area in the cell.
• Endoplasmic reticulum-the communications network linking the various structures of the cell; involved in the production of various substances important for growth and metabolism.

Don't feel overwhelmed by all of this information. We will remind you of the names and functions of these cellular structures as we talk about the important things they do in the plant!