Nutrition Basics: Energy and Carbohydrates

Questions and Answers

What are the main nutrients that the body uses for energy and how many kcal per gram do they provide?

Vitamins (7 kcal)

Lipids (9 kcal) (correct)

Protein (4 kcal) (correct)

Carbohydrates (4 kcal) (correct)

Which nutrient is the main source of fuel for cells, especially in the brain, nervous system, and red blood cells?

Carbohydrates

What is glycogen?

A carbohydrate made of multiple units of glucose with a highly branched structure.

What are the two forms in which carbohydrates are readily available?

Blood glucose and glycogen Signup and view all the answers

What does the Food and Nutrition Board of the Institute of Medicine recommend to obtain adequate energy?

45% to 65% of the calories we consume each day be from carbohydrates Signup and view all the answers

What is glucose?

A 6-carbon monosaccharide that usually exists in a ring form. Signup and view all the answers

What is sugar?

A simple carbohydrate with the chemical composition (CH2O) Signup and view all the answers

What is starch?

A carbohydrate made of multiple units of glucose attached together. Signup and view all the answers

What is fiber?

Substances in plant foods not digested by the processes in the stomach or small intestine. Signup and view all the answers

What serves as the basic unit of all carbohydrate structures?

Monosaccharides Signup and view all the answers

What are the most common monosaccharides?

Glucose, fructose, and galactose Signup and view all the answers

What is the major monosaccharide found in the body?

Glucose Signup and view all the answers

What is sucrose?

Fructose bonded to glucose; table sugar Signup and view all the answers

What is fructose?

A 6-carbon monosaccharide that usually exists in a ring form. Signup and view all the answers

What is high-fructose corn syrup?

Corn syrup that has been manufactured to contain between 42% and 90% fructose. Signup and view all the answers

What is galactose?

A 6-carbon monosaccharide that usually exists in a ring form. Signup and view all the answers

What is lactose?

Glucose bonded to galactose; also known as milk sugar. Signup and view all the answers

What are disaccharides?

Class of sugars formed by the chemical bonding of 2 monosaccharides. Signup and view all the answers

What happens to starch when a starch is broken down?

It forms maltose when broken down to 2 glucose molecules bonded together. Signup and view all the answers

What is fermentation?

The conversion of carbohydrates to alcohols, acids, and carbon dioxide without the use of oxygen. Signup and view all the answers

What are polysaccharides also known as?

Complex carbohydrates or starch Signup and view all the answers

What is amylose?

A digestible straight-chain type of starch composed of glucose units. Signup and view all the answers

What is amylopectin?

A digestible branched-chain type of starch composed of glucose units. Signup and view all the answers

Amylose comprises about 20% of the digestible starch found in vegetables, beans, breads, pasta, and rice.

True Signup and view all the answers

What makes up the remaining 80% of digestible starches in your diet?

Amylopectin Signup and view all the answers

What is cellulose?

A type of fiber; a complex carbohydrate in plants. Signup and view all the answers

Enzymes that break down starches to glucose and other related sugars act only at the beginning of a glucose chain.

False Signup and view all the answers

What is the result of amylopectin being a branched chain?

It provides many more sites for enzyme action, digesting more rapidly. Signup and view all the answers

What are the major storage sites for glycogen?

Liver and muscles Signup and view all the answers

What is fiber mostly made up of?

Polysaccharides Signup and view all the answers

What is cellulose?

An undigestible nonfermentable straight-chain polysaccharide made of glucose molecules. Signup and view all the answers

What is hemicellulose?

A nonfermentable fiber containing xylose, galactose, glucose, and other monosaccharides bonded together. Signup and view all the answers

What is pectin?

A viscous fiber containing chains of galacturonic acid and other monosaccharides. Signup and view all the answers

What are mucilages?

A viscous fiber consisting of chains of galactose, mannose, and other monosaccharides. Signup and view all the answers

What are lignins?

A nonfermentable fiber made up of a multiringed alcohol structure. Signup and view all the answers

What is dietary fiber?

Fiber found in food. Signup and view all the answers

What are whole grains?

Grains containing the entire seed of the plant, including the bran, germ, and endosperm. Signup and view all the answers

What is nonfermentable fiber?

A fiber that is not metabolized by intestinal bacteria. Signup and view all the answers

What is viscous fiber?

A fiber that is readily fermented by bacteria in the large intestine. Signup and view all the answers

What is an example of viscous (soluble) fiber?

Pectins, gums, and mucilages. Signup and view all the answers

What is an example of nonfermentable (insoluble) fiber?

Cellulose in the skin of an apple. Signup and view all the answers

What is functional fiber?

Fiber added to foods that has been shown to provide health benefits. Signup and view all the answers

Why are plant-based foods the best sources of starch?

Plants store glucose in the form of starches. Signup and view all the answers

Fiber is found in many of the same foods as starch (whole grains, beans, and potatoes).

True Signup and view all the answers

Where are soluble fibers found?

In the skins and flesh of many fruits and berries. Signup and view all the answers

How can individuals with low natural dietary fiber intake obtain health benefits?

Fiber supplements or additives. Signup and view all the answers

What are foods with moderate amounts of carbohydrate calories?

Peas, broccoli, oatmeal, dry beans, and fat-free milk. Signup and view all the answers

In foods with carbohydrate calories, what is the carbohydrate content diluted by?

Either by protein or by fat. Signup and view all the answers

What are the top 10 foods with the highest percentage of carbohydrates?

<ol> <li>Table sugar (99.9%) 2. Hard candies (98-99%) 3. Sugary cereals (90-93%) 4. Dried fruits (75-90%) 5. Cakes (84%) 6. Low-fat crackers (82%) 7. Jams (64-68%) 8. Hash browns (35%) 9. Low-fat dressings (32%) 10. Pizza (22-30%)</li> </ol> Signup and view all the answers

What are the 5 subgroups of vegetables organized by nutrient content?

<ol> <li>Dark green 2. Starchy 3. Red and orange 4. Beans and peas 5. Other</li> </ol> Signup and view all the answers

What key nutrients do dairy products provide and what benefits do they provide?

Calcium, potassium, vitamin D, and protein. Signup and view all the answers

Sugars provide calories and sweetness, while sugar alcohols only provide calories.

False Signup and view all the answers

What are the different types of sugar alcohols?

Sorbitol, mannitol, xylitol, maltitol. Signup and view all the answers

What are the different types of alternative sweeteners?

Stevia, luo han guo, aspartame, acesulfame-K, saccharin, sucralose, neotame. Signup and view all the answers

What food offers essentially the same nutritional value as other simple sugars?

Honey Signup and view all the answers

What is sorbitol?

Alcohol derivative of glucose that yields about 3 kcal/g. Signup and view all the answers

What is xylitol?

Alcohol derivative of the 5-carbon monosaccharide xylose. Signup and view all the answers

What is Acceptable Daily Intake (ADI)?

Estimate of the amount of a sweetener that an individual can safely consume. Signup and view all the answers

What is saccharin?

Alternative sweetener that yields no energy to the body. Signup and view all the answers

What was saccharin thought to increase the risk of based on laboratory studies?

Bladder cancer. Signup and view all the answers

What is aspartame?

Alternative sweetener made of 2 amino acids and methanol. Signup and view all the answers

What are the components of aspartame?

2 amino acids: phenylalanine and aspartic acid; methanol. Signup and view all the answers

Aspartame causes tooth decay.

False Signup and view all the answers

What is phenylketonuria (PKU)?

Disease caused by a defect in the liver's ability to metabolize phenylalanine. Signup and view all the answers

What is sucralose?

Alternative sweetener that has chlorines in place of hydroxyl groups on sucrose. Signup and view all the answers

What is neotame?

General-purpose, nonnutritive sweetener that is approximately 7000 to 13000 times sweeter than sugar. Signup and view all the answers

What is acesulfame K?

Alternative sweetener that yields no energy to the body. Signup and view all the answers

What is stevia?

Alternative sweetener derived from South American shrub. Signup and view all the answers

What can be viewed as the start of carbohydrate digestion?

Food preparation. Signup and view all the answers

What happens to starches when they're heated?

The starch granules start to swell as they soak up water. Signup and view all the answers

Where does enzymatic digestion of starch take place?

It begins in the mouth. Signup and view all the answers

What is amylase?

Starch-digesting enzyme from the salivary glands or pancreas. Signup and view all the answers

Where does most carbohydrate digestion and absorption take place?

In the small intestine. Signup and view all the answers

What is maltase?

An enzyme that digests maltose to 2 glucoses. Signup and view all the answers

What is sucrase?

An enzyme that digests sucrose to glucose and fructose. Signup and view all the answers

What is lactase?

An enzyme that digests lactose to glucose and galactose. Signup and view all the answers

What is lactose maldigestion?

Primary lactose maldigestion occurs when lactase production declines without reason. Signup and view all the answers

What is the percentage of the world that has the primary form of lactose maldigestion?

75% Signup and view all the answers

What is lactose intolerance?

A condition where symptoms appear due to severe lactose maldigestion. Signup and view all the answers

What percentage of adults in North America show signs of decreased lactose digestion?

25% Signup and view all the answers

What have studies shown about individuals with decreased lactase production?

They can tolerate 1/2 to 1 cup of milk with meals. Signup and view all the answers

Obtaining enough calcium and vitamin D from the diet is much easier if milk and milk products are included.

True Signup and view all the answers

How will combining lactose-containing foods with other foods help an individual obtain enough calcium and vitamin D?

Certain properties of foods can enhance digestion rates. Signup and view all the answers

What is the process of carbohydrate absorption?

<ul> <li>Glucose and galactose follow an active absorption process.</li> </ul> Signup and view all the answers

What happens after the liver metabolizes the monosaccharides and transforms it into glucose?

<ul> <li>It releases glucose into the bloodstream.</li> </ul> Signup and view all the answers

Study Notes

Energy and Nutrients

Carbohydrates provide 4 kcal/g, lipids 9 kcal/g, and protein 4 kcal/g.
Carbohydrates are the primary fuel source for cells, especially for the brain, nervous system, and red blood cells.

Glycogen

Glycogen is a branched carbohydrate made of glucose units, stored in the liver and muscles, serving as the body's glucose reservoir.

Forms of Carbohydrates

Available carbohydrate forms include blood glucose and glycogen.
Recommended intake from carbohydrates: 45% to 65% of daily calories.

Sugars and Their Types

Glucose is a 6-carbon monosaccharide, commonly found in a ring form and as dextrose in blood.
Sucrose is a disaccharide made of glucose and fructose, commonly known as table sugar.
Lactose consists of glucose and galactose, primarily found in milk.
Maltose is formed from two glucose molecules.

Fiber and Types

Fiber consists of indigestible plant substances that add bulk to feces, divided into:
- Dietary fiber (natural in foods)
- Functional fiber (added to food for health benefits)
Types of fiber include cellulose (undigestible), hemicellulose, pectin, mucilages, and lignins, with varying fermentability.

Starch and Its Composition

Starch is a digestible carbohydrate made of glucose units.
Amylose (straight-chain) and amylopectin (branched-chain) are digestible starch types, with amylopectin comprising about 80% of starches in the diet.

Health Benefits of Fiber

Plant-based foods are rich sources of starch and fiber; beans, grains, and vegetables are ideal for health benefits.
Fiber can be soluble (viscous, like pectins) or insoluble (non-fermentable, like cellulose).

Sweeteners and Alternative Sweeteners

Sugar alcohols such as sorbitol, mannitol, xylose, and maltitol are used in diet foods, providing fewer calories than sucrose.
Alternative sweeteners include stevia, aspartame, saccharin, and sucralose, which vary greatly in sweetness and sources.

Digestion of Carbohydrates

Carb digestion begins during food preparation (cooking), continues in the mouth with salivary amylase, and primarily occurs in the small intestine.
Enzymes like maltase, sucrase, and lactase break down disaccharides and polysaccharides.

Lactose and Intolerance

Primary lactose maldigestion affects 75% of the world, though not all exhibit symptoms; lactose intolerance leads to digestive issues upon consuming dairy.
Adults in North America show decreased lactose digestion in 25% of cases.

Metabolism and Absorption of Carbohydrates

Glucose and galactose are absorbed actively, while fructose uses facilitated diffusion.
The liver metabolizes monosaccharides into glucose, releasing it into the bloodstream for energy use or storage.

General Notes

Foods with high carbohydrate content include table sugar, sugary cereals, and baked goods, with sugar providing energy and sweetness.
Successfully combining lactose-containing foods with non-dairy foods can aid nutrient absorption and digestion.

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Description

Explore the fundamentals of energy and nutrients with a focus on carbohydrates. Learn about the different forms of carbohydrates, their functions, and recommended intake levels. This quiz covers essential sugars, glycogen, and fiber types crucial for a balanced diet.