Chapter 4

Question 1

Bioenergetics

Answer 1

The study of energy in the human body

Question 2

Metabolism

Answer 2

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

• main source of chemical energy are carbohydrates, fats & protein

Question 3

Exercise metabolism

Answer 3

The examination of bioenergectics as it relates to the unique physiologic changes & demands placed on the body during exercise

Question 4

Substrates

Answer 4

The matter or substance on which an enzyme acts

MAIN SUBSTRATES

• proteins
• carbs
• lipids (fats)

Question 5

Carbohydrates

Answer 5

Fuel & energy for all day activity; organic compounds of carbon, hydrogen & oxygen, which include starches, cellulose, and sugars and are an important source of energy

• All carbodhydrates 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, which serves as the body’s main source of fuel

Question 7

Glycogen

Answer 7

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

• it is store IN liver & muscle cells

Question 8

Fat

Answer 8

1 of the 3 main classes of foods & a source of energy in the body. Fats help the body use some vitamins & keep the skin healthy. They also serve as energy stores for the body

• In food there are 2 types of fat
  1. Saturated
  2. Unsaturated

Question 9

Triglycerides

Answer 9

The chemical or substrate form in which most fat exists 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 & usually sulfur and that have several essential biologic compounds

• Significant fuel during starvation
• Rarely supplies much energy during exercise & is ignored as significant fuel for energy metabolism

Question 11

Gluceoneogenisis

Answer 11

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

Question 12

Adenosine Triphosphate

Answer 12

Energy storage & transfer unit within the cell of the body

Question 13

Adenosine Diphosphate

Answer 13

A high-energy compound occurring in all cells from which adenosine triphosphate (ATP) is formed

Question 14

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

Answer 14

1. ATP-PC System
2. The glycolytic system (glycolysis)
3. The oxidative system (oxidative phosphorylation)

Question 15

ATP - PC System

Answer 15

“The Phosphagen System”; ATP + PC = Phosphagens
The process of creating a new ATP molecule from a phosphocreatine (PC) molecule (ATP-PC System) is the simplest and fastest of the energy systems and occurs without the presence of oxygen (anaerobic)

• provides energy for primarily high-intensity, short-duration bouts of exercise or activity; seen in power & strength forms of training
• this system is activated at the onset of activity, regardless of intensity, because of its ability to produce energy very rapidly in comparison with the other systems

Question 16

Glycolysis

Answer 16

The process of glycolysis does not begin until either glucose or glycogen is broken down into glucose-6-phosphate

The end result of glycolysis in which glucose or glycogen is broken down to either pyruvic acid (aerobic glycolysis) or lactic acid (anaerobic glycolysis) is 2 ATP for each molecule or unit of glucose and 2 ATP from each unit of glycogen

This system produces a significantly greater amount of energy than the ATP-PC system, but it too is limited to approx. 30 - 50 seconds of duration. Most workout will place a greater stress on this system than others because typical repetition range of 8 - 12 reps falls within this time frame

Question 17

The Oxidative System

Answer 17

The most complex of the 3 energy systems; it uses substrates with the aid of oxygen to generate ATP; the 3 oxidative (aerobic) processes are:

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

Question 18

Without oxygen during glycolysis, what is the end product?

Answer 18

Lactic acid

Question 19

With oxygen during glycolysis, what is the end product?

Answer 19

Pyruvic acid

In the presence of oxygen, pyruvic acid is converted into an important molecule in metabolism called acetyl coenzyme A (acetyl CoA). This is an important molecule because it contributes substrates for use in the 2nd process of oxidative production of ATP, called the Krebs cycle

Question 20

B (beta) oxidation

Answer 20

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 & ultimately lead to the production of additional ATP

Question 21

Excess Post Exercise Oxygen Consumption (EPOC)

Answer 21

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

Question 22

When would energy be mostly derived from anaerobic metabolism?

Answer 22

When an athlete begins an activity

Question 23

What usually happens after 90 minutes of exercise?

Answer 23

The majority of muscle glycogen stores are depleted