http://www.ck12.org Chapter 3. Chemical Interactions
FIGURE 3.70
Foods that are good sources of starches.Cellulose
Cellulose is another complex carbohydrate that is a polymer of glucose. However, glucose molecules are bonded
together differently in cellulose than they are in starches. Cellulose molecules bundle together to form long, tough
fibers, as you can see in theFigure3.71. Have you ever eaten raw celery? If you have, then you probably noticed that
the stalks contain long, stringy fibers. The fibers are mostly cellulose. Cellulose is the most abundant biochemical
compound. It makes up the cell walls of plants and gives support to stems and tree trunks. Cellulose also provides
needed fiber in the human diet. We can’t digest cellulose, but it helps keep food wastes moving through the digestive
tract.
Summary
- Carbohydrates are biochemical compounds that include sugars, starches, and cellulose. They contain carbon,
hydrogen, and oxygen, and they are used mainly for energy by living things. - Sugars are simple carbohydrates such as glucose, which the cells of living things use for energy.
- Starches are complex carbohydrates that are polymers of glucose. Starches are used by plants to store energy.
Consumers get starches by eating plants. They break down the starches to sugar for energy. - Cellulose is another complex carbohydrate that is a polymer of glucose. It is the most abundant biochemical
compound. It makes up the cell walls of plants and provides fiber in the human diet.
Vocabulary
- carbohydrate: Biochemical compound such as sugar, starch, or cellulose that contains oxygen in addition to
carbon and hydrogen.
Explore More
Watch the video about carbohydrates at the following URL, and then answer the questions below.