Ch 4: Exercise metabolism and Bioenergetics Flashcards
Adenosine Triphosphate (ATP)
Energy storage and transfer unit within the cells of the body
Bioenergetics
The study of energy in the human body.
Metabolism
All of the chemical reactions that occur in the body to maintain itself. Metabolism is the process in which nutrients are acquired, trasnported. used, and disposed of by the body.
Exercise metabolism
The examination of bioenergetics as it relates to the unique physiologic changes and demands placed on the body during exercise.
Substrates
The material or substance on which an enzyme acts.
The effect of a lack of carbohydrates
Fatigue, poor mental function, lack of endurance and stamina
Carbohydrates are digested into…
Glucose
Fats are digested into….
Triglycerides
What are the three main substrates?
Carbohydrates, Fats, and Proteins
What is it called when amino acids are used to assist in energy production?
Gluconeogenesis
Carbohydrates
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.
Glucose
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.
Glycogen
The complex carbohydrate molecule used to store carbohydrates in the liver and muscle cells. When carbohydrate energy is needed, glycogen is converted into glucose for use by the muscle cells.
Fat
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.
Triglycerides
The chemical or substrate form in which most fat exists in food as well as in the body.
Protein
Amino acids linked by peptide bonds, which consist of carbon, hydrogen, nitrogen, oxygen, and usually sulfur, and that have several essential biologic compounds.
Gluconeogenesis
The formation of glucose from noncarbohydrate sources, such as amino acids.
Adenosine diphosphate (ADP)
A high-energy compound occurring in all cells from which adenosine triphosphate (ATP) is formed. It’s also the biproduct of ATP being split for energy.
About how much energy from ATP is used for muscle contraction
Only about 40% the rest is released as heat.
Phosphorylation
ATP creation by the addition of a phosphate to ADP
What are the three metabolic pathways in which cells can generate ATP?
- The ATP-PC system
- The glycolitic system (glycolysis)
- The oxidative system (oxidative phosphorylation)
The ATP-PC System (of energy production)
The process of creating a new ATP molecule from a phosphocreatine molecule is the simplest and fastest of the energy systems, and occurs without the presence of oxygen.
The system provides energy for primarily high-intensity, short-duration bouts of exercise or activity.
Like power lifting or short sprinting.
Glycolisis
The chemical breakdown of glucose or glycogen to produce ATP.
The two types of
Glycolysis
- Glucose/Glycogen –> pyruvic acid: aerobic glycolysis
- Glucose/Glycogen –> lactic acid: anaerobic glycolysis
Which produces more ATP through glycolysis Glucose or Glycogen?
Glycogen.
Glucose produces 2 ATP per mole and Glycogen produces 3 ATP per mole
What is the duration of the Glycolytic energy system? (Glycolysis)
Approximately 30-50 seconds of work
What is the duration of the ATP-PC energy stystem?
About 10 -15 seconds or work
The oxidative system
The process that uses substrates with the aid of OXYGEN to generate ATP.
What are the three processes of the oxidative system?
- Aerobic glycolysis
- The Krebs cycle
- The electron transport chain (ETC)
ß-oxidization
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.
What is the recovery period of the ATP-PC cycle
Approximately 90 seconds
Respiratory Quotient (RQ)
The amount of carbon dioxide expired, divided by the amount of oxygen consumed, measured during rest or at steady state of exercise using a metabolic analyzer.
What RQ ratio indicates that solely carbohydrates are being used during steady-state exercise
1.0
What RQ ratio indicates that solely fats are being used during steady-state exercise
0.7
What RQ ratio indicates a mix of carbohydrates and fats are fueling steady-state exercise
0.17 - 0.99
How does RQ relate to the myth of the fat-burning zone?
While lower intensity exercise my decrease RQ and therefore use a higher percentage of fat as energy, it is likely that increasing total calories burned by increasing intensity will contribute to higher use of fat as an energy source even though the ratio of carbohydrates to fats used as fuel will favor carbohydrate use.
