BIOL 320 Chapter 25 Textbook

What is nutrition, and what processes does it include?

Nutrition is the process by which the body obtains and uses certain components of food.

The process includes (1) digestion, (2) absorption, (3) transportation, and (4) cell metabolism.

Distinguish between a nutrient and an essential nutrient.

Nutrients are substances taken into the body that are used by the cells of the body to produce energy, to provide building blocks for new molecules, and to function in other chemical reactions.

Essential nutrients, also called indispensable nutrients, are substances that must be ingested because the body cannot manufacture them at all or cannot manufacture adequate amounts of them.

List the six major classes of nutrients.

1. Carbohydrates

2. Lipids

3. Proteins

4. Vitamins

5. Minerals

6. Water

Define a kilocalorie. State the number of kilocalories supplied by a gram of carbohydrate, a gram of lipid, and a gram of protein.

A kilocalorie is 1000 calories and is used to express the larger amounts of energy supplied by foods and released through metabolism.

One gram of carbohydrates or proteins will release about 4kcal of energy.

One gram of a lipid will release about 9kcal of energy.

List the five food groups shown in MyPlate. How is the importance of eating fruits and vegetables indicated in MyPlate?

(1) Fruits, (2) vegetables, (3) grains, (4) proteins, and (5) dairy food groups.

To emphasize the importance of making healthful food choices, half the plate is fruits and vegetables.

What are the most common monosaccharides in the diet? What are the sources of the three common disaccharides: sucrose, maltose, and lactose?

Glucose and fructose are the most common monosaccharides in the diet.

The principal sources of sucrose are sugarcane, sugar beets, maple sugar, and honey.

Maltose comes from malt sugar, derived from germinating cereals.

Lactose is known as milk sugar.

Complex carbohydrates. How does the body use them?

Complex carbohydrates are polysaccharides, which consist of many glucose molecules bound together to form long chains, such as starch, glycogen, and cellulose.

The body uses them as energy-storage located primarily in the muscle and liver.

How does the body use glucose and other monosaccharides?

Glucose provides energy to produce ATP molecules.

What is the recommended daily consumption of carbohydrates?

The Acceptable Macronutrient Distribution Range for carbs is 45-65% of total kilocalories.

What is the major source of lipids in the diet? What are some other sources?

About 95% of lipids in the human diet are triglycerides.

The remaining 5% of lipids include cholesterol and phospholipids.

Distinguish between saturated and unsaturated fats. What are trans fats?

Saturated fats and oils have only single covalent bonds between the carbon atoms of their fatty acids. They can be found in the fats of meat, dairy products, eggs, coconut oil, and palm oil.

Unsaturated fats and oils have one or more double covalent bonds between the carbon atoms of their fatty acids.

Trans fats are a type of processed fat made by saturating an unsaturated oil though the hydrogenation. Meaning, that hydrogen gas is bubbled through the oil to produce a change in molecular shape that solidifies it.

How does the body use triglycerides, cholesterol, prostaglandins, and lecithin?

Triglycerides are important sources of energy that can be used to produce ATP. Some cells, such as skeletal muscle cells, derive most of their energy from triglycerides.

Prostaglandins are involved in activities such as inflammation, blood clotting, tissue repair, and smooth muscle contraction.

Lecithin is a part of the plasma membrane and is used to construct the myelin sheath around the axons of neurons. It is also found in bile and helps emulsify lipids.

Describe the recommended dietary intake of lipids. List the essential fatty acids, and state food sources that contain them.

Distinguish between essential, conditionally essential, and nonessential amino acids. Explain the difference between complete and incomplete protein foods.

Describe the functions of proteins in the body.

What is the AMDR of proteins? What is nitrogen balance? What would place a person in negative nitrogen balance?

What are vitamins, essential vitamins, and provitamins?

Name the fat-soluble vitamins and the water-soluble vitamins.

List some of the functions of vitamins in the body.

What are Recommended Dietary Allowances (RDAs)? Why are they useful?

What are some symptoms of specific vitamin deficiencies?

What are minerals? What is the daily requirement for major minerals?

List several minerals the body needs and a function of each.

What are the Reference Daily Intakes and the Daily Reference Values? When combined, what reference set of values is established?

Define % Daily Values. The % Daily Values appearing on food labels is based on how many kilocalories per day?

How are metabolism, anabolism, and catabolism related? How is the energy derived from catabolism used to drive anabolic reactions?

How does the removal of hydrogen atoms from nutrient molecules result in a loss of energy from the nutrient molecule?

Describe the four phases of glycolysis. What are the products of glycolysis?

What determines whether the pyruvate produced in glycolysis is used in aerobic respiration or anaerobic respiration?

Describe the two phases of anaerobic respiration. How many ATP molecules result from anaerobic respiration?

What happens to the lactate produced in anaerobic respiration once O2 becomes available?

Define aerobic respiration, and list its products. Describe the four phases of aerobic respiration.

Why is the citric acid cycle a cycle? What molecules are produced as a result of the citric acid cycle?

What is the function of the electron-transport chain? Describe the process of chemiosmosis that occurs during ATP production.

In aerobic respiration, how many ATP molecules are produced from one molecule of glucose through glycolysis, the citric acid cycle, and the electron-transport chain?

Why is the total number of ATP produced in aerobic respiration listed as 32? Why could that number be different?

Write the summary equation for the aerobic breakdown of one glucose molecule.

What is beta-oxidation? Explain how it results in ATP production.

What are ketone bodies, how are they produced, and for what are they used? What occurs when there is an excess?

What is accomplished by transamination and oxidative deamination?

How are proteins (amino acids) used to produce energy?

Distinguish among the processes of glycogenesis, lipogenesis, glycogenolysis, and gluconeogensis.

When does the absorptive state occur?

What happens to glucose, lipids, and amino acids during the absorptive state?

When does the postabsorptive state occur?

Why is it important to maintain blood glucose levels during the postabsorptive state? Name three sources of this glucose.

What is metabolic rate? How is it measured?

What is BMR? What factors can alter BMR?

What is the thermic effect of food?

BMR, the thermic effect of food, and muscular activity each account for what percentage of total energy expenditure?

How are kilocaloric input and output adjusted to maintain body weight?

What is free energy? How much free energy is lost as heat from

What are four ways that heat is exchanged between the body and the environment?

How is body temperature maintained behaviorally in a cold environment? How is body temperature maintained physiologically in a hot environment?

How does the hypothalamus regulate body temperature?