Introduction

Chapter 4. Nutrition, Metabolism, Enzymes

Interactive Study Guide
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Welcome to the Interactive Study Guide for Chapter 4: Nutrition, Metabolism, Enzymes! This Study Guide will help you master your understanding of the chapter's Driving Questions, using interactive Infographics and activities, as well as targeted assessment questions. Click "Next" to get started, or select a Driving Question from the drop-down menu to the right.

The Peanut Butter Project:

A doctor’s crusade to end malnutrition in Africa one spoonful at a time.

DRIVING QUESTIONS

  • What are the macronutrients and micronutrients provided by food?
  • What are essential nutrients?
  • What are enzymes and how do they work?
  • What are the consequences of a diet lacking sufficient nutrients?

Driving Question 1

What are the macronutrients and micronutrients provided by food?

Why should you care?

We are what we eat. Research over the past 40 years or more has increasingly pointed to a proper diet—one that includes the right kinds of nutrients from the right kinds of foods—as a major component of overall health, longevity, and quality of life. When it comes to food, knowledge is power: knowing what kinds of nutrients are in different kinds of foods is the first step toward making good food choices.

What should you know?

To fully answer this Driving Question, you should be able to:

  1. List the three dietary macronutrients and the foods in which each predominates.
  2. Explain why a healthful diet must include a variety of food sources to provide all necessary macronutrients.
  3. Define and give examples of the types of micronutrients.

Infographic Focus

The infographics most pertinent to the Driving Question are 4.2, 4.3, and Table 4.1.

Test Your Vocabulary

Choose the correct term for each of the following definitions:

Term Definition
Nutrients—including carbohydrates, proteins, and fats, that organisms must ingest in large amounts to maintain good health.
Nutrients, including vitamins and minerals, that organisms must ingest in small amounts to maintain good health.
An inorganic chemical element required by organisms for normal growth, reproduction, and tissue maintenance; examples are calcium, iron, potassium, and zinc.
An organic molecule required in small amounts for normal growth, reproduction, and tissue maintenance.
The ability to do work, including building complex molecules.
Components in food that the body needs to grow, develop, and repair itself.
Table
999
Try again.
Correct.
Incorrect.

List the three dietary macronutrients and the foods in which each predominates.

1.

Complete the following table to identify the three macronutrients and foods in which they predominate:

Macronutrient
Source Carbohydrates Protein Fats
Food Type 1
Food Type 2
Table
2
Correct.
Try again.
Incorrect.

Explain why a healthful diet must include a variety of food sources to provide all necessary macronutrients.

2.

Use the information in the table and in Infographic 4.2 to explain why you need to eat a variety of foods to acquire all the macronutrients you need.
You need to eat a variety of foods because no single food contains enough of all three nutrients for your body to sustain itself.

Define and give examples of the types of micronutrients.

5.

Define the terms “micronutrient,” “mineral,” and “vitamin” and give an example of each.
Micronutrients are nutrients that organisms need to ingest in small amounts to maintain their health. An example of a micronutrient is vitamin C. Minerals are inorganic chemical elements that the body needs for normal development. An example of a mineral is zinc. Vitamins are organic molecules the body needs in order to maintain health. An example of a vitamin is vitamin B12. Vitamins and minerals are micronutrients.

Driving Question 2

What are essential nutrients?

Why should you care?

The macronutrients we consume are broken down into smaller subunits; these, in turn, are used to build the molecules that make up our cells and cell components.

In contrast, essential nutrients are nutrients that our bodies need to function normally but that cannot be made by the body itself. Therefore, essential nutrients must be obtained through the diet. This emphasizes the fact that when it comes to healthful food choices, knowledge is power.

What should you know?

To fully answer this Driving Question, you should be able to:

  1. Describe how the macronutrients in your diet are broken down and what their building blocks are.
  2. Describe how the building blocks of macronutrients are reassembled and some of their functions in our cells.
  3. Define an essential nutrient.

Infographic Focus

The infographics most pertinent to the Driving Question are 4.3, 4.5, and Table 4.1.

Test Your Vocabulary

Choose the correct term for each of the following definitions:

Term Definition
Nutrients that can’t be made by the body so must be obtained from the diet.
Nutrients, including carbohydrates, proteins, and fats, that organisms must ingest in large amounts to maintain health.
Amino acids the human body cannot synthesize so must be obtained from food.
Table
999
Try again.
Correct.
Incorrect.

Describe how the macronutrients in your diet are broken down and what their building blocks are.

10.

What process breaks down the macronutrients in our food into their building blocks? Where does this process take place? (Hint: it may occur in more than one place.)
Digestion breaks down the macronutrients in food into their building blocks. Digestion starts in the mouth as saliva and chewing begin to break down food. Digestion continues in the stomach as gastric juices break down the food further. The process continues in the small intestine, where 95% of the nutrients from the food are absorbed into the bloodstream. While absorption of minerals and water continues in the large intestine and colon, the actual digestion of the food is typically finished by this point.

Describe how the building blocks of macronutrients are reassembled and some of their functions in our cells.

11.

Where are the macromolecule building blocks reassembled into new macromolecules? How do building blocks arrive at that location?
The macromolecule building blocks are reassembled into new macromolecules in cells. Building blocks arrive at cells through the blood stream.

Define "essential nutrient."

13.

1. An essential nutrient ___________ (mark "true" for all that apply)

a. can be added to foods.

b. can be found naturally in certain foods.

c. can be manufactured in the body if sufficient subunits of macronutrients are available.

d. has no effect on the health of an individual.

Correct.
Incorrect.

Related Vocabulary

14.

Define each term, illustrate as appropriate, and note the similarities and differences between terms.
• Ready-to-use therapeutic food (RUTF)
• Starch
• Starvation
• Malnutrition

Driving Question 3

What are enzymes, and how do they work?

Why should you care?

Without enzymes to speed the rate of chemical reactions, complex life could not exist. Missing or malfunctioning enzymes lie at the heart of many diseases and syndromes, including phenylketonuria (PKU) (see the warning labels on foods containing Nutrasweet) and Tay-Sachs disease. When we digest food chemically, we rely on a number of digestive enzymes, each of which targets a specific macromolecule or group of molecules. In one of the first stages of digestion, for example, the enzymes in our saliva start breaking down complex carbohydrates; they can’t, however, break down proteins. Enzymes from the pancreas take on that job when food arrives in the small intestine.

What should you know?

To fully answer this Driving Question, you should be able to:

  1. Compare and contrast the ways in which enzymes facilitate catabolic and anabolic reactions.
  2. Predict the effect of an enzyme on the activation energy of a reaction.
  3. Explain the role of micronutrients in enzyme function.

Infographic Focus

The infographics most pertinent to the Driving Question are 4.4, 4.5, and 4.6.

Test Your Vocabulary

Choose the correct term for each of the following definitions:

Term Definition
An inorganic chemical element required by organisms for normal growth, reproduction, and tissue maintenance; examples are calcium, iron, potassium, and zinc.
An inorganic substance, such as a metal ion, required to activate an enzyme.
A molecule to which an enzyme binds and upon which it acts.
Any chemical reaction that breaks down complex molecules into simpler molecules.
The energy required for a chemical reaction to proceed. Enzymes accelerate reactions by reducing their activation energy.
The process of speeding up the rate of a chemical reaction (e.g., by enzymes).
A small organic molecule, such as a vitamin, required to activate an enzyme.
The part of an enzyme that binds to substrates.
Any chemical reaction that combines simple molecules to build more complex molecules.
An organic molecule required in small amounts for normal growth, reproduction, and tissue maintenance.
All biochemical those occurring in an organism, including those that break down food molecules and reactions that build new cell structures.
Nutrients, including vitamins and minerals, that organisms must ingest in small amounts to maintain good health.
A protein that speeds up the rate of a chemical reaction.
Table
999
Try again.
Correct.
Incorrect.

Compare and contrast the ways in which enzymes facilitate catabolic and anabolic reactions.

15.

What is the similarity in the steps by which enzymes facilitate catabolic and anabolic chemical reactions?
The similarity is that the substrate binds to the active site of the enzyme and causes the enzyme to change shape and catalyze a reaction.

Predict the effect of an enzyme on the activation energy of a reaction.

17.

Which reaction would have the lowest activation energy for an enzyme that binds its substrate only in the presence of a cofactor?

A.
B.
C.
D.
2
Try again.
Correct.
Incorrect.

Explain the role of micronutrients in enzyme function.

18.

Why do enzymes need micronutrients to do their jobs?
Micronutrients act as cofactors that activate enzymes and allow them to bind to their substrates.

Related Vocabulary

19.

Define each term, illustrate as appropriate, and note the similarities and differences between terms.
• Potassium
• Iron
• Vitamin C
• Vitamin A
• Zinc
• Iodine
• Calcium

Driving Question 4

What are the consequences of a diet lacking sufficient nutrients?

Why should you care?

One of the most important things you can do to ensure your long-term health and fitness is to eat a balanced diet that (1) provides the nutrients you need in appropriate amounts, (2) supplies adequate (but not too many) calories, and (3) minimizes foods that increase your risk of developing long-term disorders such as diabetes, osteoporosis, and heart disease. When your regular diet lacks sufficient nutrients, your body cannot perform necessary tasks efficiently or at all.

What should you know?

To fully answer this Driving Question, you should be able to:

  1. Describe how vitamins and minerals have essential functions and the effects on the body of not consuming them in proper amounts.

Infographic Focus

The infographics most pertinent to the Driving Question are 4.1, 4.6, 4.7, and Table 4.1.

Describe how vitamins and minerals have essential functions and the effects on the body of not consuming them in proper amounts.

20.

List three vitamins and three minerals that are essential for proper body function.
Three vitamins that are essential for proper body function are C, D and B12. Three minerals that are essential for proper body function are calcium, potassium and iron.

Compare and contrast a diet lacking nutrients for children in a middle class American family versus children in a poverty stricken Malawi family.

24.

Think about typical middle-class American children’s diet. In your opinion, what does that diet look like?
Typical children from a middle-class American family would more than likely have access to all of the basic food groups and nutrient sources. They would also likely have access to foods containing vital micronutrients, essential amino acids, and so on.

Related Vocabulary

27.

Define each term, illustrate as appropriate, and note the similarities and differences between terms.
• Project Peanut Butter
• BioCassava Plus

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