Complex Carbohydrates and Polysaccharides

Questions and Answers

What are complex carbohydrates composed of?

Monosaccharides bonded together, forming large chainlike structures.

What is the primary function of complex carbohydrates in plants and animals?

To store energy or make certain structural components.

What are the two types of polysaccharides that contain hundreds of glucose molecules?

Starch and glycogen.

In what form do plants primarily store glucose as starch?

Amylopectin. Signup and view all the answers

What are some rich food sources of starch?

Bread and cereal products, vegetables such as corn and squash, and tubers such as potatoes. Signup and view all the answers

Where does the human body store limited amounts of glucose as glycogen?

Muscles and the liver. Signup and view all the answers

Why are animal foods not typically sources of glycogen?

Because muscle glycogen breaks down soon after an animal dies. Signup and view all the answers

How many kcal does each gram of starch supply?

4 kcal. Signup and view all the answers

What is the fiber content of 1 cup of cooked black beans?

15.0 g Signup and view all the answers

Rank the following foods from highest to lowest in fiber content per serving: green peas, baked potato, and prunes.

prunes (3.5 g) < baked potato (4.0 g) < green peas (7.2 g) Signup and view all the answers

How much fiber is in 1 cup of strawberries?

3.3 g Signup and view all the answers

What is the fiber content of 1 cup of chickpeas?

10.6 g Signup and view all the answers

Which of the following breakfast cereals has the highest fiber content per serving: Kellogg's Raisin Bran or Kellogg's All-Bran?

Kellogg's All-Bran (9.9 g) Signup and view all the answers

What is the fiber content of 1 slice of whole-grain bread?

1.9 g Signup and view all the answers

What is the primary function of fiber in plants?

Supportive structures and protective seed coats Signup and view all the answers

What type of bonds connect monosaccharides to form complex carbohydrates?

Bonds that humans cannot digest Signup and view all the answers

What is the only type of fiber that is not a carbohydrate?

Lignin Signup and view all the answers

What happens to fiber that is not used by gut microbiota?

It contributes to stools (fecal residue) and is eventually eliminated Signup and view all the answers

What are the two types of dietary fiber?

Soluble fiber and insoluble fiber Signup and view all the answers

What happens to soluble fiber in water?

It dissolves or swells Signup and view all the answers

What is a rich source of insoluble fiber?

Whole-grain products, including brown rice Signup and view all the answers

What happens to fiber content when grains undergo refinement?

Much of the fiber content is lost Signup and view all the answers

What is a benefit of soluble fiber in the body?

It can help reduce blood cholesterol levels Signup and view all the answers

What type of foods provide dietary fiber?

Only plant foods Signup and view all the answers

Study Notes

Complex Carbohydrates

Complex carbohydrates (polysaccharides) are composed of monosaccharides bonded together, forming large chainlike structures.
Plants and animals use complex carbohydrates to store energy or make certain structural components such as stems and leaves.
The most common dietary polysaccharides consist of hundreds of glucose molecules and include digestible and nondigestible forms.

Starch and Glycogen

Starch and glycogen are polysaccharides that contain hundreds of glucose molecules bound together.
Plants store glucose as starch, primarily in the form of amylopectin, in their seeds, roots, and fleshy underground stems called tubers.
Rich food sources of starch include bread and cereal products made from wheat, rice, barley, and oats; vegetables such as corn, squash, beans, and peas; and tubers such as potatoes, yams, taro, cassava, and jicama.
Each gram of starch supplies 4 kcal.

Fiber

Fiber is a complex carbohydrate composed of monosaccharides connected by bonds that humans cannot digest.
Cellulose, hemicellulose, pectin, gums, beta-glucans, and mucilages are polysaccharide forms of fiber.
Lignin is the only type of fiber that is not carbohydrate.
Fiber is not digested, but it may be metabolized (fermented) by gut microbiota.
Fiber contributes to stools (fecal residue) that are eventually eliminated during bowel movements.

Types of Fiber

There are two types of dietary fiber, soluble fiber and insoluble fiber.
Soluble fiber dissolves or swells in water, while insoluble fiber does not dissolve in water.
Rich sources of soluble fiber include oat bran, oatmeal, beans, apples, carrots, oranges, and psyllium seeds.
Rich sources of insoluble fiber include whole-grain products, including brown rice.
Plant foods usually contain both soluble and insoluble fiber.

Benefits of Fiber

Soluble fiber can help reduce blood cholesterol levels.
Insoluble fiber may ease bowel movements.
Fiber provides important health benefits when added to the diet in adequate amounts.