Chapter 4

Question 1

bioenergetics

Answer 1

The study of energy in the human body.

Question 2

metabolism

Answer 2

All of the chemical reactions that occur in the body to maintain itself. Metabolism is the process in
which nutrients are acquired, transported, used, and disposed of by the body.

Question 3

exercise metabolism

Answer 3

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

Question 4

substrates

Answer 4

The material or substance on which an enzyme acts.

Question 5

carbohydrates

Answer 5

—Organic compounds of carbon, hydrogen, and oxygen, which include starches, cellulose, and
sugars, and are an important source of energy. All carbohydrates are eventually broken down in the body to glucose,
a simple sugar

Question 6

glucose

Answer 6

A simple sugar manufactured by the body from carbohydrates, fat, and to a lesser extent protein; it serves
as the body’s main source of fuel.

Question 7

glycogen

Answer 7

The complex carbohydrate molecule used to store carbohydrates in the liver and muscle cells. When
energy is needed, glycogen is converted into glucose for use by the muscle cells.

Question 8

fat

Answer 8

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 9

tryglycerides

Answer 9

The chemical, or substrate, form in which most fats exist in food as well as in the body

Question 10

protein

Answer 10

Amino acids linked by peptide bonds which consist of carbon, hydrogen, nitrogen, oxygen, and usually
sulfur, and that have several essential biologic compounds

Question 11

gluconeogenesis

Answer 11

The formation of glucose from non-carbohydrate sources such as amino acids

Question 12

Adenosine tri-phosphate ATP

Answer 12

Energy storage and transfer unit within the cells of the body

Question 13

Adenosine Diphosphate

Answer 13

—A high-energy compound occurring in all cells from which ATP is formed.

Question 14

β-oxidation

Answer 14

The breakdown of triglycerides into smaller subunits, called free fatty acids (FFAs), to convert FFAs
into acyl-CoA molecules, which then are available to enter the Krebs cycle and ultimately lead to the production of
additional ATP.

Question 15

excess post-exercise oxygen consumption EPOC

Answer 15

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

exercise.

Question 16

lack of carbohydrates in the diet cause

Answer 16

cause fatigue, poor mental function, and lack of endurance and stamina

Question 17

Th e primary end product aft er the digestion of carbohydrates is the
formation of

Answer 17

glucose

Question 18

how does glucose enter the cells

Answer 18

with insulin

Question 19

where is glycogen stored?

Answer 19

liver and muscle cells

Question 20

For one cycle on a cross bridge for muscle contraction ___ ATP is needed

Answer 20

2

Question 21

Only about ___% of the energy released from ATP is actually used for
cellular work, like muscle contraction. Th e remainder is released as heat

Answer 21

40

Question 22

When the enzyme ATPase combines with an ATP molecule, it splits the last phosphate
group away, releasing a large amount of free energy, approximately ____ kcal per unit of
ATP

Answer 22

7.3

Question 23

ATP equation

Answer 23

ATP ⇔ ADP Pi energy release

Question 24

what are the 3 metabolic pathways in which cells can generate ATP?

Answer 24

1. Th e ATP-PC system
2. Th e glycolytic system (glycolysis)
3. Th e oxidative system (oxidative phosphorylation)

Question 25

PC or CP

Answer 25

phosphocreatine

Question 26

ATP-PC System

Answer 26

ATP needs to be replenished by transferring phosphate from phosphocreatine to an ADP molecule, enough energy is produced to create one cross-bridge cycle, this is the simplest and fastest of the energy systems, anaerobic, for high intensity short durations such as power and strength training, this system is activated at the onset of activity regardless of activity because it is so rapid

Question 27

glycolysis

Answer 27

anaerobic means to produce ATP glucose or glycogen must be converted to glucose 6 phosphate glucose uses 1 ATP in this process glycogen doesn’t, produces 2ATP for glucose and 3 ATP for glycogen, produces more energy than ATP-PC system , limited to about 30-50 seconds, (usually workouts with rep ranges of 8-12)

Question 28

Oxidative System

Answer 28

energy system that uses substrates with the aid of oxygen to generate ATP (aerobic)

Question 29

3 oxidative / aerobic systems

Answer 29

1. Aerobic glycolysis
2. Th e Krebs cycle
3. Th e electron transport chain (ETC)

Question 30

anaerobic glycolysis produces

Answer 30

lactic acid

Question 31

aerobic glycolysis produces

Answer 31

pyruvic acid, and eventually converted to Acetyl COa then used in the Krebs cycle to produce 2 units of ATP

Question 32

Why are Carbohydrates the preferred substrate for the oxidative production of ATP?

Answer 32

fat oxidation produces
far more ATP per molecule of fat compared with a molecule of carbohydrate, fat oxidation requires more oxygen to produce ATP; thus carbohydrates are the preferred fuel
substrate for the oxidative production of ATP

Question 33

Th e end results of the aerobic metabolism of carbohydrates and fats are

Answer 33

water and carbon dioxide

Question 34

Which takes longer? the aerobic breakdown of glucose and fat, the anaerobic metabolism of glucose, or the ATP-PC cycle?

Answer 34

Th e
aerobic breakdown of glucose and fat takes much longer than the anaerobic metabolism of glucose and far longer than the ATP-PC cycle.

Question 35

Energy is used to form the ________ that facilitate muscle contraction.

Answer 35

myosin actin cross bridges

Question 36

intensity and duration of exercise

are ____ related.

Answer 36

inversely

Question 37

As the duration of exercise increases (up to approximately

2 minutes), the primary source of energy comes from __________ but some energy comes from the other pathways as well.

Answer 37

anaerobic metabolism of glucose

(anaerobic glycolysis),

Question 38

bioenergetics of exercise can be indirectly measured in

Answer 38

(e.g., treadmill, cycle ergometer, rowing ergometer, cross-country ski
simulator, swimming fl ume) while measuring the concentrations of oxygen and carbon
dioxide and volume of expired air.

Question 39

steady-state exercise

Answer 39

, is exercise performed at a
constant pace (intensity). For example, steady-state exercise could be described as walking at a brisk pace of 4 mph or 15:00 minutes per mile for a total of 15 minutes or 1 mile.

Question 40

Th e body prefers _______ because carbon dioxide and

water are more easily eliminated

Answer 40

aerobic or oxidative metabolism

Question 41

respiratory Quotient RQ

Answer 41

is the amount of carbon dioxide (CO 2
 ) expired divided
by the amount of oxygen (O 2
 ) consumed, measured during rest or at steady state of
exercise using a metabolic analyzer

Question 42

RQ in steady state of exercise indications

Answer 42

During steady-state exercise, an RQ of 1.0
indicates that carbohydrate is supplying 100% of the fuel, whereas an RQ of 0.7 indicates that fat is supplying 100% of the fuel for metabolism. Any RQ between 0.7 and
1.0 indicates a mixture of carbohydrates and fats are fueling metabolism.