Plant Cells
A tree, an ant, and a dog are very different, yet they are all similar in one way – they are made up
of cells. A cell is the basic unit, or building block, that makes up all living things. The cells in a
living organism work together to carry out the life processes that help the organism stay alive.
Some of these life processes include taking in nutrients, giving off wastes, growing, and
reproducing.
The cells of living things cannot be seen with the human eye alone. They are so tiny; they are
only visible under a microscope. With a microscope, we can see that even though the cells of
plants and animals are similar to each other, they have some different parts and different shapes.
Plant cells are usually rectangular in shape and are made up of a number of important parts.
These parts include the cell wall, the cell membrane, cytoplasm, the nucleus, chloroplasts, and
vacuoles.
The Cell Wall – In plants, a thick cell wall surrounds each cell. The cell wall protects the
delicate contents of the cell.
The Cell Membrane – Lining the inside of the cell wall is the cell membrane. The cell
membrane is very thin. It controls what comes in to the cell and what leaves the cell (food, water,
oxygen, wastes).
Cytoplasm – Filling the inside of the cell is a jelly-like material called cytoplasm. The rest of
the cell’s parts are located in the cytoplasm.
The Nucleus – Near the center of the cytoplasm is a round structure called the nucleus. The
nucleus is the cell’s command center. It controls all of the cell’s activities (making, using,
storing food).
Chloroplasts – Small round chloroplasts can also be found in the cytoplasm. They use sunlight
to produce plant sugars (food).
Vacuoles – Also located in the cytoplasm are structures called vacuoles. Vacuoles store the food
and water that the cell will use later. Some vacuoles also store waste materials until the cell is
ready to get rid of them.
Think! How is your classroom like a plant cell?