Vacuoles — Structure & Function

How Do Cells Store Nutrients?

A vacuole is a membrane-bound sac that contains water and other substances. You can think of it as the refrigerator of the cell because it stores salts, carbohydrates, sugars, and water.

Look at the image above and find the vacuoles in the plant and animal cells (I highlighted them). We can see that plants have a single, large central vacuole which takes up a lot of the cell's volume. It is normally filled with cell sap—a collection of water and nutrients. Animal cells have multiple smaller versions of this organelle.

$$\color{#8925AE}{\text{Vocabulary Review:}}$$

$\color{#8925AE}{\text{Vacuole}}$ : Organelle that contains water and nutrients. Refrigerator of the cell

$\color{#8925AE}{\text{Golgi Apparatus}}$ : Stores, sorts, and modifies proteins and lipids. Post office of the cell

$\color{#8925AE}{\text{Cytoskeleton}}$ : Helps the cell maintain its shape and assists with movement. Skeleton of the cell

$\color{#8925AE}{\text{Mitochondria}}$ : Make ATP (energy). Powerhouse of the cell

$\color{#8925AE}{\text{Ribosome}}$ : Creates polypeptide chains and proteins. Factory of the cell

$\color{#8925AE}{\text{Endoplasmic Reticulum}}$ : The smooth ER makes lipids for the cellular membrane. The rough ER assembles proteins and transports them into and out of the cell

$\color{#8925AE}{\text{Nucleus}}$ : Contains the genetic material, DNA, of the cell. Brain of the cell

The Cellular Storage Center

Vacuoles are storage sacs found in most eukaryotic cells. They are membrane-bound and filled with a fluid containing organic or inorganic molecules.

Plant cells have one large vacuole, while animal cells tend to have several smaller ones.

Let's see what they look like in plant and animal cells:

Plants use this organelle to store large amounts of water because thirsty plants can't get up and get a drink like animals can. Plants need a place to store water when they get it.

Role in Structure

This organelle also plays an important role in helping plant cells keep their structure. When a plant's vacuole is full, the plant stands up straight. When it's empty, the plant wilts. This happens because vacuoles are responsible for a plant cell's turgor pressure.

Think of it like a balloon in the cell. When it's full, it takes up a bunch of space inside the cell walls, pushing on them. When it's empty, it deflates. The cell walls don't have anything pushing on them, so they slump inward.

If many cells in the plant have slumping cell walls, the whole plant looks wilted. But when you water a plant, the cells fill up their vacuoles and the plant "comes back to life".

(Video) Vacuoles Function in Cells

by MooMooMath and Science

Both animal cells and plant cells have vacuoles. These compartments are used to store water, waste products, and old organelles. Some of them can even fuse with the plasma membrane to help the cell remove waste.

However, the structure and function of this organelle does vary between plant and animal cells. Watch the video above to find out more about this important organelle.