Scientists Say: Cellulose

Cellulose is the main building block of plant and algae cell walls

The purest natural form of cellulose is in cotton, which is used to make t-shirts and other clothes you might have hanging in your closet.

vitapix/E+/Getty Images

Cellulose (noun, “Sell-YOO-lohs”)

Let’s keep it short and sweet: Cellulose is a chain of sugar molecules. In particular, it is made up of linked molecules of the sugar glucose. That chain structure makes cellulose a polymer. In fact, it is the most abundant natural polymer on Earth.

Plants, algae and some bacteria make cellulose. Some bacteria ooze this stuff and form biofilms. These are communities of bacterial cells that form a sticky slime and glom onto surfaces.

In plants and algae, cellulose is the main building block of cell walls. It makes those cells stiff, which is why plant stems and tree branches are so sturdy. The purest natural form of cellulose is cotton. Over 90 percent of cotton is cellulose. Wood, meanwhile, is about 50 percent cellulose.

Plant-eating animals like cows and sheep can digest cellulose. People can’t. But cellulose is still a key part of our diet. Why? Cellulose is a source of dietary fiber. That fiber keeps food moving through the gut, preventing digestive traffic jams. Cellulose is also important for many types of manufacturing. Cotton is used to make clothes like t-shirts and jeans. Cellulose from wood gets turned into paper. This polymer also goes into making cardboard, plastic wrap, coffee filters, sponges and many other products.

In a sentence

To replace polluting plastic glitter, scientists have used cellulose from wood pulp to create shimmery, plant-based glitter.

Check out the full list of Scientists Say.

Maria Temming is the assistant editor at Science News for Students. She has bachelor's degrees in physics and English, and a master's in science writing.

More Stories from Science News for Students on Life