Chapter 8: Exercise Metabolism and Bioenergetics

Question 1

Adenosine triphosphate (ATP)

Answer 1

A high-energy molecule that serves as the main form of energy in the human body; known as the energy currency of the body.

Question 2

Bioenergetics

Answer 2

The study of energy in the human body.

Question 3

Metabolism

Answer 3

All of the chemical reactions that occur in the body to maintain itself.

Question 4

Exercise metabolism

Answer 4

The examination of bioenergetics as it relates to the unique physiologic changes and demands placed on the body during exercise.

Question 5

First law of thermodynamics

Answer 5

Energy cannot be created or destroyed but merely converted from one form to another.

Question 6

Macronutrients

Answer 6

Food substances required in large amounts to supply energy and include protein, carbohydrate, and fat.

Question 7

Substrates

Answer 7

Intermediate forms of nutrients used in metabolic reactions to create adenosine triphosphate.

Question 8

Glucose

Answer 8

The simplest form of carbohydrate used by the body for energy.

Question 9

Glycogen

Answer 9

Glucose that is deposited and stored in bodily tissues, such as the liver and muscle cells; the storage form of carbohydrate.

Question 10

Ventilatory threshold 1 (VT1)

Answer 10

The point at which the body uses an equal mix of carbohydrate and fat as fuel sources

Question 11

Ventilatory threshold 2 (VT2)

Answer 11

The point where glucose provides nearly all of the energy for the activity.

Question 12

Fats

Answer 12

One of the three main classes of foods and a source of energy in the body. Fats help the body use some vitamins and keep the skin healthy. They also serve as energy stores for the body. In food, there are two types of fats: saturated and unsaturated.

Question 13

Triglyceride

Answer 13

The chemical or substrate form in which most fat exists in food as well as in the body.

Question 14

Free fatty acids

Answer 14

The by-products of the breakdown of stored or consumed fats, metabolized exclusively via the aerobic pathway, which uses oxygen to create adenosine triphosphate.

Question 15

Protein

Answer 15

Amino acids linked by peptide bonds; the building blocks of body tissues.

Question 16

Essential amino acid (EAA)

Answer 16

Amino acid that must be obtained through the diet as the body does not make it; there are nine essential amino acids.

Question 17

Nonessential amino acids

Answer 17

Amino acids that can be synthesized by the body and do not, under normal circumstances, need to be obtained in the diet.

Question 18

Negative energy balance

Answer 18

When calorie intake is lower than the number of calories expended.

Question 19

Gluconeogenesis

Answer 19

The formation of glucose from noncarbohydrate sources (proteins and fats).

Question 20

ketogenesis

Answer 20

The formation of ketone bodies from nonfat sources, such as certain amino acids.

Question 21

Ketone bodies

Answer 21

Water-soluble molecules produced in the liver as a result of fatty acid oxidation. They can then be oxidized in the mitochondria to produce adenosine triphosphate.

Question 22

Ketosis

Answer 22

A state of carbohydrate depletion where the liver manufactures ketone bodies to meet energy demands that free fatty acid oxidation cannot support.

Question 23

Exogenous ketones

Answer 23

Isolated ketone bodies usually consumed in supplement form.

Question 24

Insulin resistance

Answer 24

The inability of the cells to respond to insulin; occurs in type 2 diabetes.

Question 25

Ketoacidosis

Answer 25

Metabolic acidosis induced by very high levels of ketone bodies such as seen in type 1 diabetes or severe insulin resistance.

Question 26

Mechanical work

Answer 26

The physical processes that move the body and keep it alive, such as muscle contraction.

Question 27

Adenosine diphosphate (ADP)

Answer 27

A high-energy compound occurring in all cells from which adenosine triphosphate is formed.

Question 28

Phosphorylation

Answer 28

The addition of a phosphate group to a molecule, such as in the transfer of a phosphate group to adenosine diphosphate to create adenosine triphosphate.

Question 29

ATP-PC System

Answer 29

An energy system that provides energy very rapidly, for approximately 10–15 seconds, via anaerobic metabolism.

Question 30

Anaerobic

Answer 30

Processes relating to the absence of oxygen.

Question 31

Glycolysis

Answer 31

A metabolic process that occurs in the cytosol of a cell that converts glucose into pyruvate and adenosine triphosphate. Anaerobic glycolysis refers to when this process occurs in the absence of oxygen.

Question 32

Oxidative phosphorylation

Answer 32

A series of reactions inside the mitochondria that uses oxygen to produce adenosine triphosphate.

Question 33

Aerobic

Answer 33

Processes relating to, involving, or requiring oxygen.

Question 34

Deamination

Answer 34

The breakdown of amino acids into substrates that can be used for energy metabolism.

Question 35

Electron transport chain (ETC)

Answer 35

A series of protein complexes that transfer protons and electrons received from the citric acid cycle through a series of reactions to create adenosine triphosphate.

Question 36

Acetyl coenzyme A

Answer 36

Produced by the breakdown of carbohydrates through glycolysis and by the fatty acids through beta-oxidation and is the precursor for these substrates to the citric acid cycle.

Question 37

Beta-oxidation

Answer 37

The first step in the process to break down fats via oxidative phosphorylation.

Question 38

Steady-state aerobic exercise

Answer 38

Aerobic exercise that remains at a relatively constant intensity, including a stable heart rate and oxygen consumption.

Question 39

Excess post exercise oxygen consumption (EPOC)

Answer 39

The state in which the body’s metabolism is elevated after exercise.

Question 40

Total daily energy expenditure (TDEE)

Answer 40

The total amount of energy expended in one day.

Question 41

Kilocalorie (kcal)

Answer 41

One food calorie. Also, the amount of energy needed to raise one kilogram of water by one degree Celsius.

Question 42

Resting metabolic rate (RMR)

Answer 42

The rate at which the body expends energy (calories) when fasted and at complete rest, such as asleep or lying quietly.

Question 43

Exercise activity thermogenesis (EAT)

Answer 43

The calories expended through structured exercise or training.

Question 44

Thermic effect of food (TEF)

Answer 44

The energy required to digest, absorb, and process nutrients that are consumed.

Question 45

Nonexercise activity thermogenesis (NEAT)

Answer 45

Energy expenditure through daily activities outside of structured exercise, such as walking, completing household chores, and taking the stairs.

Question 46

Physical activity level (PAL)

Answer 46

The number of calories a person expends through physical activity and structured exercise.

Question 47

Metabolic equivalent (MET)

Answer 47

A measurement used to describe the energy cost of physical activity as multiples of resting metabolic rate. One MET is 3.5 mL of oxygen consumption per kilogram per minute.