p.6
ATP Production Pathways
What is the role of ATP in energy production?
ATP stores energy from chemical bonds in food.
p.44
ATP Production Pathways
How much more ATP does fat oxidation yield compared to glucose oxidation?
Approximately 3 to 4 times more ATP.
p.54
Bioenergetics and Metabolism
What is the focus of the course MSR 4123?
Introduction to Functional Anatomy & Exercise Physiology.
p.3
Bioenergetics and Metabolism
What is bioenergetics?
The process of converting substrates into energy.
p.52
Muscle Fiber Types and Oxidative Capacity
What physiological change occurs in mitochondria due to endurance training?
More and larger mitochondria are developed.
p.22
Controlling Energy Production Rates
What is a rate-limiting enzyme?
An enzyme that can create a bottleneck at an early step in a metabolic pathway.
p.47
Bioenergetics and Metabolism
How do the three energy systems interact during activities?
All three systems interact for all activities, with no one system contributing 100%.
p.24
ATP Production Pathways
What is the process of synthesizing ATP from its by-products?
ADP + Pᵢ + energy → ATP (via phosphorylation).
p.19
Controlling Energy Production Rates
What role do enzymes play in chemical reactions?
They facilitate the breakdown (catabolism) of substrates.
p.18
Controlling Energy Production Rates
How is energy released in metabolic pathways?
At a controlled rate based on enzyme activity.
p.17
Controlling Energy Production Rates
How is the rate of energy production controlled?
By the availability of primary substrates.
p.46
Protein as an Energy Source
Why is the energy yield from protein oxidation not easy to determine?
Due to the presence of nitrogen.
p.22
Controlling Energy Production Rates
What is the effect of a rate-limiting enzyme on a metabolic reaction?
It can create a bottleneck, slowing down the overall reaction.
p.17
Controlling Energy Production Rates
What occurs when there is an excess of a given substrate?
Cells rely on that energy substrate more than others.
p.23
ATP Production Pathways
Why is ADP considered less useful than ATP?
Because it is a lower-energy compound.
p.23
ATP Production Pathways
How is ATP stored in the body?
In small amounts until needed.
p.50
Muscle Fiber Types and Oxidative Capacity
What are the factors that determine oxidative capacity in muscles?
Enzyme activity, fiber type composition, endurance training, and O2 availability versus O2 need.
p.27
ATP Production Pathways
What happens to ATP stores during exercise using the phosphocreatine system?
ATP is recycled until phosphocreatine is used up.
p.25
ATP Production Pathways
What is the oxidative system?
An aerobic metabolism pathway for ATP synthesis.
p.52
Muscle Fiber Types and Oxidative Capacity
What effect does endurance training have on type II muscle fibers?
It enhances their oxidative capacity.
p.23
ATP Production Pathways
What is the primary stored energy molecule in cells?
ATP (Adenosine Triphosphate).
p.38
ATP Production Pathways
What is the final stage of carbohydrate oxidation?
Electron transport chain.
p.47
Bioenergetics and Metabolism
What typically happens during a specific task regarding energy systems?
One energy system often dominates for a given task.
p.4
Bioenergetics and Metabolism
What is metabolism?
Chemical reactions in the body.
p.35
ATP Production Pathways
What is glycolysis?
A metabolic pathway that provides energy for approximately 2 minutes of maximal exercise.
p.53
Bioenergetics and Metabolism
How does the body respond to increased ATP demand during exercise?
By increasing the rate of oxidative ATP production, O2 intake at the lungs, and O2 delivery by the heart and vessels.
p.44
Oxidative and Anaerobic Metabolism
Is the oxidation of fat faster or slower than glucose oxidation?
Slower than glucose oxidation.
p.39
Glycolysis and Anaerobic Metabolism
Can glycolysis occur in the presence of oxygen?
Yes, glycolysis can occur with or without O2.
p.51
Muscle Fiber Types and Oxidative Capacity
What is a characteristic of Type I muscle fibers?
They have greater oxidative capacity.
p.11
Fat as an Energy Source
Why is fat considered an efficient substrate?
Because it provides a high caloric value and is efficient for storage.
p.35
ATP Production Pathways
What is needed for exercise durations longer than 2 minutes?
Another energy pathway beyond glycolysis.
p.29
ATP Production Pathways
How does CK control the rate of ATP production?
Through a negative feedback system.
p.5
Energy Measurement and Caloric Values
What is 1 calorie (cal)?
The heat energy required to raise 1 g of water from 14.5 °C to 15.5 °C.
p.30
Controlling Energy Production Rates
How does exercise training affect serum creatine kinase (CK) activity?
Exercise training increases oxidative capacity and attenuates exercise-induced ultrastructural damage.
p.39
Glycolysis and Anaerobic Metabolism
What is the ATP yield of glycolysis in the presence of oxygen?
The same as anaerobic glycolysis.
p.6
Overview of Energy Substrates
What are the primary substrates used as fuel for exercise?
Carbohydrate, fat, and protein.
p.51
Muscle Fiber Types and Oxidative Capacity
What is found in high concentrations in Type I fibers?
High oxidative enzyme concentrations.
p.43
Fat as an Energy Source
What does the rate of free fatty acid (FFA) entry into muscle depend on?
The concentration gradient of FFA.
p.42
Fat as an Energy Source
What are the products of triglyceride breakdown?
1 glycerol and 3 free fatty acids (FFAs).
p.53
Controlling Energy Production Rates
What is the limitation of oxygen storage in muscles?
Oxygen storage is limited; it must be used or it will be lost.
p.23
ATP Production Pathways
What happens to ATP when it breaks down?
It converts to ADP, which is a lower-energy compound.
p.46
Protein as an Energy Source
Why is protein metabolism generally considered minimal in energy yield estimates?
Because estimates often ignore protein metabolism.
p.30
Bioenergetics and Metabolism
What is one benefit of exercise training in aged horses according to the study?
It increases oxidative capacity in skeletal muscle.
p.15
Protein as an Energy Source
What are the two main purposes for converting protein into FFAs?
For energy storage and as a cellular energy substrate.
p.27
ATP Production Pathways
How long can the ATP recycling via the phosphocreatine system sustain maximal exercise?
Approximately 3-15 seconds.
p.50
Muscle Fiber Types and Oxidative Capacity
What is the relationship between O2 availability and O2 need in determining oxidative capacity?
Oxidative capacity is influenced by the balance between O2 availability and O2 need.
p.9
Carbohydrate as an Energy Source
What happens to all carbohydrates consumed?
They are converted to glucose.
p.22
Controlling Energy Production Rates
How does negative feedback influence enzyme activity?
It slows the overall reaction and prevents runaway reactions.
p.1
Controlling Energy Production Rates
What is a key factor in controlling energy production during exercise?
The rate of energy production.
p.27
ATP Production Pathways
What is the chemical reaction involving phosphocreatine and creatine kinase?
PCr + creatine kinase → Cr + Pi + energy.
p.15
Protein as an Energy Source
What can protein be converted into besides glucose?
Free Fatty Acids (FFAs) through lipogenesis.
p.19
Controlling Energy Production Rates
What do enzymes lower to facilitate chemical reactions?
They lower the activation energy.
p.30
Controlling Energy Production Rates
What type of damage does exercise training help to reduce in skeletal muscle?
Exercise-induced ultrastructural damage.
p.39
ATP Production Pathways
What happens to pyruvic acid in the presence of oxygen?
It is converted to acetyl-CoA and enters the Krebs cycle.
p.6
Overview of Energy Substrates
Which elements are found in carbohydrates, fats, and proteins?
Carbon, hydrogen, oxygen, and nitrogen.
p.21
Controlling Energy Production Rates
How does enzyme activity affect product formation?
More enzyme activity results in more product.
p.2
Overview of Energy Substrates
What are substrates in the context of energy production?
Fuel sources from which we make energy.
p.34
Bioenergetics and Metabolism
What is a major con of the glycolytic system?
Low ATP yield and inefficient use of substrate.
p.34
Bioenergetics and Metabolism
What happens to pyruvic acid in the absence of oxygen?
It converts to lactic acid.
p.25
ATP Production Pathways
How many ATP synthesis pathways are there?
Three ATP synthesis pathways.
p.9
Carbohydrate as an Energy Source
What is the primary ATP substrate for muscles and the brain?
Glucose, derived from carbohydrates.
p.7
Overview of Energy Substrates
What are the primary substrates for fuel during resting?
50% carbohydrate and 50% fat.
p.43
Fat as an Energy Source
How does FFA concentration affect its transport into muscle fibers?
Higher FFA concentration leads to a higher rate of transport into muscle fibers.
p.5
Energy Measurement and Caloric Values
How can energy release be measured?
By calculating the heat produced.
p.24
ATP Production Pathways
What are the reactants needed to synthesize ATP?
ADP, inorganic phosphate (Pᵢ), and energy.
p.19
Controlling Energy Production Rates
Do enzymes start chemical reactions or set ATP yield?
No, they do not start chemical reactions or set ATP yield.
p.5
Energy Measurement and Caloric Values
What is the relationship between kcal and dietary Calories?
1 kcal = 1 Calorie (dietary).
p.1
Interaction Among Energy Systems
What is important about the interaction among energy systems?
It affects overall energy production during exercise.
p.18
Controlling Energy Production Rates
What role do enzymes play in energy production?
They control the rate of energy release in metabolic pathways.
p.17
Controlling Energy Production Rates
What is the mass action effect?
Substrate availability affects metabolic rate.
p.26
ATP Production Pathways
What type of metabolism does the ATP - PCr system utilize?
Anaerobic, substrate-level metabolism.
p.46
Protein as an Energy Source
What is a unique aspect of protein metabolism compared to carbohydrates and fats?
The presence of nitrogen.
p.53
Energy Measurement and Caloric Values
How can O2 levels entering and leaving the lungs be used in exercise physiology?
They provide an accurate estimate of O2 use in muscle.
p.31
ATP Production Pathways
What is the ATP yield of the glycolytic system per mole of substrate?
2 to 3 mol ATP/1 mol substrate.
p.12
Fat as an Energy Source
Which component of fat is used to make ATP?
Only free fatty acids (FFAs).
p.25
ATP Production Pathways
What is the ATP-PCr system?
An anaerobic metabolism pathway for ATP synthesis.
p.23
ATP Production Pathways
How is energy released from ATP?
By breaking down ATP into ADP and inorganic phosphate (Pᵢ) using water and ATPase.
p.24
ATP Production Pathways
Can ATP synthesis occur in the absence of oxygen?
Yes, it can occur in both the absence and presence of O₂.
p.27
ATP Production Pathways
What is the role of phosphocreatine (PCr) in ATP recycling?
PCr helps in the reassembly of ATP through the reaction with creatine kinase.
p.2
Overview of Energy Substrates
What are the primary substrates used to produce ATP?
Carbohydrate, fat, and protein.
p.50
Muscle Fiber Types and Oxidative Capacity
Do all muscles exhibit maximal oxidative capabilities?
No, not all muscles exhibit maximal oxidative capabilities.
p.12
Fat as an Energy Source
Into what components must fat be broken down for ATP production?
Free fatty acids (FFAs) and glycerol.
p.39
ATP Production Pathways
What is the role of acetyl-CoA in metabolism?
It enters the Krebs cycle for further energy production.
p.25
ATP Production Pathways
What is the glycolytic system?
An anaerobic metabolism pathway for ATP synthesis.
p.17
Controlling Energy Production Rates
What happens when more substrate is available?
Higher pathway activity occurs.
p.47
Bioenergetics and Metabolism
What occurs during transition periods among energy systems?
There is more cooperation among the energy systems.
p.13
Fat as an Energy Source
What role does Malonyl-CoA play in fat oxidation during exercise?
Malonyl-CoA regulates fat oxidation in human skeletal muscle.
How many enzymatic reactions occur in the glycolytic system?
10 to 12 enzymatic reactions.
p.34
Bioenergetics and Metabolism
How does lactic acid affect muscle function?
It impairs glycolysis and muscle contraction.
p.34
Bioenergetics and Metabolism
What is a key advantage of the glycolytic system?
It allows muscles to contract when oxygen is limited.
p.39
Glycolysis and Anaerobic Metabolism
What is glycolysis?
A metabolic process that breaks down carbohydrates to produce ATP.
p.10
Carbohydrate as an Energy Source
Why must the body rely on dietary carbohydrates?
To replenish limited glycogen stores.
p.13
Fat as an Energy Source
How does carnitine contribute to fat oxidation?
Carnitine facilitates the transport of fatty acids into the mitochondria for oxidation.
p.9
Carbohydrate as an Energy Source
Where is extra glucose stored in the body?
As glycogen in the liver and muscles.
p.26
ATP Production Pathways
Why is the ATP - PCr system important?
Because ATP stores are very limited, this pathway is used to reassemble ATP.
p.25
ATP Production Pathways
What must the body do to maintain energy levels?
The body must constantly synthesize new ATP.
p.13
Fat as an Energy Source
What is the primary focus of the study by Roepstorff et al.?
The regulation of fat oxidation in human skeletal muscle during exercise.
p.13
Fat as an Energy Source
Which physiological process is being examined in relation to Malonyl-CoA and carnitine?
Fat oxidation during exercise.
p.27
ATP Production Pathways
Can the energy from phosphocreatine (PCr) be used for cellular work?
No, PCr energy cannot be used for cellular work directly.
p.34
Bioenergetics and Metabolism
What type of exercise does the glycolytic system support?
Shorter-term, higher-intensity exercise.
p.50
Muscle Fiber Types and Oxidative Capacity
How does enzyme activity affect oxidative capacity?
Higher enzyme activity can enhance oxidative capacity.
p.50
Muscle Fiber Types and Oxidative Capacity
What role does fiber type composition play in oxidative capacity?
Different fiber types have varying oxidative capabilities, influencing overall capacity.
p.50
Muscle Fiber Types and Oxidative Capacity
How does endurance training impact oxidative capacity?
Endurance training can improve oxidative capacity in muscles.
