Animal cell and plant cell

Two closely related organization plans

The animal cell and the plant cell share a common organization: both have a membrane, a cytoplasm and, most often, a nucleus. But they differ through several structures specific to each kingdom.

What the plant cell has in addition

• A rigid cell wall (made of pectin and cellulose), which surrounds the membrane and gives the plant cell a fixed shape, usually rectangular or polygonal.
• A large vacuole, a kind of sac filled with water and dissolved substances, which often takes up most of the cell's volume and maintains its turgidity (its firmness).
• Chloroplasts, green organelles responsible for photosynthesis, absent in animals.

What characterizes the animal cell

• No cell wall: only a flexible membrane delimits the cell, which allows it to have a variable shape, sometimes rounded, sometimes very irregular (like neurons).
• No chloroplasts: animal cells cannot make their own organic matter from light, they must feed on other organisms.
• Small and few vacuoles, or even none at all.

Observing the difference under the microscope

(plant cell observed under the microscope):
sharp, angular outline --> rigid wall
large clear space in the center --> vacuole
small green dots --> chloroplasts

(animal cell observed under the microscope):
soft, rounded outline --> no wall
no green area --> no chloroplast

A misconception to correct

No, not all plant cells are green: root cells, for example, have no chloroplasts since they do not receive light. The chloroplast is only present in cells that carry out photosynthesis, such as those in leaves.