Chapter 3 - Bioenergetics of Exercise and Training Flashcards
Which of the following substances can be metabolized anaerobically?
a. glycerol
b. glucose
c. amino acids
d. free fatty acids
b. glucose
Which of the following reactions is the primary cause of metabolic acidosis (i.e.,the decrease in intramuscular pH during high-intensity, fatiguing exercise)?
a. ATP → ADP + Pi + H+
b. pyruvate + NADH → lactate + NAD+
c. ADP + creatine phosphate → ATP + creatine
d. fructose-6-phosphate → fructose-1,6-bisphosphate
a. ATP → ADP + Pi + H+
Which of the following energy systems produces ATP at the quickest rate?
a. phosphagen
b. aerobic glycolysis
c. fat oxidation
d. fast glycolysis
a. phosphagen
Approximately how many net ATP are produced via the oxidative energy system from the metabolism of one glucose molecule?
a. 27
b. 34
c. 38
d. 41
c. 38
Which of the following energy substrates cannot be depleted during extreme exercise intensities or durations?
a. creatine phosphate
b. glycogen
c. water
d. ATP
d. ATP
The product of the breakdown of ATP. When ATP is broken down, the end result is an XXX molecule, an inorganic phosphate, a hydrogen ion, and energy. XXX can be further broken down into AMP as a secondary source of biological energy
Adenosine diphosphate (ADP)
The final product of the breakdown of ATP and subsequent breakdown of ADP.
Adenosine monophosphate (AMP)
An important enzyme that catalyzes the hydrolysis of ATP.
Adenosine triphosphatase (ATPase)
An intermediate molecule used to drive anabolic and endergonic reactions through the energy derived from catabolic and exergonic reactions. This is composed of adenosine and three phosphate groups. The hydrolysis of XXX to ADP, and then ADP to AMP releases the energy used for biological work. XXX is considered a high energy molecule because of the large amount of energy stored in the chemical bond of the two terminal phosphate groups.
Adenosine triphosphate
A single-enzyme reaction that can rapidly replenish ATP. This reaction converts 2 ADP molecules into an ATP and AMP molecule.
Adenylate kinase reaction
Reactions and processes that depend on oxygen. These processes include the Krebs cycle, electron transport, and the entire oxidative system. These reactions occur in the mitochondria of muscle cells and require oxygen as the terminal electron acceptor.
Aerobic
The process of pyruvate being shuttled into the mitochondria and undergoing reactions resulting in ATP resynthesis. This process depends on the presence of oxygen in the mitochondria, and as such is only possible for ATP production when exercise intensity is low enough. Also known as the Krebs cycle.
Aerobic glycolysis
Process of an end-product binding to an enzyme resulting in an increase in the rate of the reaction,
Allosteric activation
Process that occurs when an end product binds to the regulatory enzyme and decreases its turnover rate, slowing the formation of the product.
Allosteric inhibition
The synthesis of larger molecules from smaller molecules. This process is often achieved using the energy gained from the catabolism of other molecules. For example, the formation of protein from amino acids.
Anabolism
Processes that do not require the presence of oxygen. These processes include the phosphagen and glycolytic systems, both of which occur in the sarcoplasm of a muscle cell.
Anaerobic
A process where ATP resynthesis occurs as pyruvate is converted to lactate. This process produces ATP at a rapid rate but is limited in duration due to the decrease in cytosolic pH.
Anaerobic glycolysis
A series of reactions in which free fatty acids are broken down, resulting in the formation of acetyl-CoA and hydrogen protons.
Beta oxidation
The flow of energy in a biological system. Primarily concerned with the conversion of macronutrients into biologically usable forms of energy.
Bioenergetics
The main amino acids that are thought to be oxidized in skeletal muscle. The BCAAs are leucine, isoleucine, and valine.
Branched-chain amino acid
The enzyme that pumps calcium into the sarcoplasmic reticulum
Calcium ATPase
The breakdown of large molecules into smaller molecules associated with a release of energy
Catabolism
The process of combining aerobic and anaerobic training, postulated to improve recovery. In heavily anaerobic sports (ie. powerlifting, Olympic lifting), the combination may be detrimental to maximum strength and power. In highly-trained endurance athletes, the addition of strength training has been shown to improve aerobic performance
Combination training
The process of transporting lactate to the liver for conversion to glucose.
Cori cycle
The enzyme that catalyzes the synthesis of ATP from ADP and creatine phosphate.
Creatine kinase
A high-energy phosphate molecule that provides the phosphate group for the synthesis of ATP from ADP in the phosphagen system
Creatine phosphate (CP)
A series of electron carriers in the electron transport chain. These pass hydrogen down the electron transport chain to form a proton concentration gradient, which provides the energy for ATP production.
Cytochrome
The consumption of molecules and substrates during energy production or other processes
Depletion
Series of proton acceptors that plays a fundamental role in oxidative metabolism
Electron transport chain (ETC)
Reactions that require energy and include anabolic processes and the contraction of the muscle
Endergonic reaction
The capacity to perform work
Energy
A molecule that can be used to produce energy (i.e. lactate)
Energy substrate
The increase in oxygen uptake following intense exercise
Excess postexercise oxygen consumption (EPOC)
Energy releasing reactions that are generally catabolic
Exergonic reaction
Also known as anaerobic glycolysis, This process produces ATP from glucose without the presence of oxygen, ultimately resulting in lactate formation
Fast glycolysis
An organic molecule produced from pyruvate during aerobic glycolysis. This molecule, alongside NADH, transport hydrogen atoms to the electron transport chain to produce ATP from ADP via phosphorylation
Flavine adenine dinucleotide (FADH2)
The formation of glucose from non-carbohydrate sources
Gluconeogenesis
The process of breaking down glycogen into glucose
Glycogenolysis
The breakdown of carbohydrate to resynthesize ATP
Glycolysis
The system of ATP production involving the splitting of glucose to resynthesize ATP. These processes can be aerobic or anaerobic depending on exercise intensity, which determines the ultimate destination for the end-products of glycolysis such as pyruvate.
Glycolytic
Brief repeated bouts of high-intensity exercise followed by intermittent recovery periods
High-intensity interval training (HIIT)
The process of splitting a molecule in a chemical reaction that depends on water. I.e hydrolysis of ATP to ADP
Hydrolysis
Pi, a phosphate molecule not bound to an organic compound. This molecule is one of the products of ATP hydrolysis
Inorganic phosphate
A method that emphasizes bioenergetic adaptations for a more efficient energy transfer within metabolic pathways using predetermined intervals of exercise and rest periods (work-to-rest ratios)
Interval training
The process that occurs when pyruvate enters the mitochondria following glycolysis. This is a crucial process during oxidative phosphorylation
Krebs cycle
A product of anaerobic glycolysis that is formed from pyruvate when there is insufficient oxygen available for the Krebs cycle
Lactate
The exercise intensity at which blood lactate begins an abrupt increase above the baseline concentration. This moment begins at approximately 50%-60% of maximal oxygen uptake in untrained individuals and at 70-80% in aerobically trained athletes.
Lactate threshold (LT)
The acidic form of lactate. Often thought to be the product of anaerobic glycolysis, it is NOT an end result of anaerobic glycolysis NOR is it the cause of rising cytosolic pH associated with fatigue
Lactic acid
This principle states that the concentration of the reactants or products in solution will drive the direction of the reactions. In enzyme-mediated reactions such as those of the phosphagen system, the rate of product formation is greatly influenced by the concentrations of reactants. Also known as the mass action effect
Law of mass action
This principle states that the concentration of the reactants or products in solution will drive the direction of the reactions. In enzyme-mediated reactions such as those of the phosphagen system, the rate of product formation is greatly influenced by the concentrations of reactants. Also known as the law of mass action
Mass action effect
The process of proton accumulation during fatigue which reduces intracellular pH, inhibits glycolytic reactions and directly interferes with the muscle’s excitation-contraction coupling
Metabolic acidosis
The metabolic needs of specific activities. An understanding of this concept is used to create efficient and productive training programs.
Metabolic specificity
The total of all catabolic/exergonic and anabolic/endergonic reactions
Metabolism
Organelle of the muscle cell where aerobic energy mechanisms occur
Mitochondria
An important single-enzyme reaction that can rapidly replenish ATP from ADP. Also known as the adenylate kinase reaction
Myokinase reaction
The enzyme that catalyzes ATP hydrolysis for crossbridge recycling
Myosin ATPase
Reactions whose speed is based on the relative concentrations of reactants and products
Near-equilibrium reactions
A product of glycolytic reactions. This is transported into the mitochondria along with pyruvate during aerobic glycolysis. These molecules ultimately enter the electron transport system, where they can be used to resynthesize ATP
Nicotinamide adenine dinucleotide (NADH)
A secondary increase in the rate of lactate accumulation that occurs at higher relative intensities of exercise. This process occurs when blood lactate accumulation reaches 4mmol/L
Onset of blood lactate accumulation (OBLA)
The resynthesis of ATP in the electron transport chain. This process required the presence of oxygen in the mitochondria
Oxidative phosphorylation
The energy system in the body that relies on oxygen for the resynthesis of ATP. This system cannot supply energy quickly due to the number of steps, however it can sustain long durations and overall can supply more ATP over time, provided the relative exercise intensities remain low enough
Oxidative system
The increased uptake of oxygen following exercise
Oxygen debt
The total anaerobic contribution to the energy cost of exercise
Oxygen deficit
The ability of a muscle cell to use oxygen
Oxygen uptake
The anaerobic system that provides ATP primarily for short-term, high-intensity activities. This system is highly active at the start of all exercise regardless of intensity. This system relies on creatine phosphate to supply the phosphate group that resynthesizes ATP from ADP
Phosphagen system
A high-energy phosphate molecule that provides the phosphate group for the synthesis of ATP from ADP in the phosphagen system
Phosphocreatine (PCr)
An enzyme that catalyzes the reaction that phosphorylates ATP during anaerobic glycolysis
Phosphofructokinase (PFK)
The process of adding inorganic phosphate to another molecule. This process is responsible for converting ADP to ATP
Phosphorylation
The end result of glycolysis. XXX is either converted to lactate in the sarcoplasm or shuttle into the mitochondria for the Krebs cycle
Pyruvate
The step in a reaction that determines the overall rate of the reaction. In the case of glycolysis, the PFK reaction of fructose-6-phosphate to fructose 1,6 bisphosphate
Rate-limiting step
The re-addition of energy substrates such as phosphagen and glycogen following depletion due to exercise
Repletion
Also known as oxidative glycolysis, this is the process of shuttling pyruvate into the mitochondria to undergo the Krebs cycle. The ATP resynthesis rate in XXX is slower due to the greater number of reactions, but can be sustained for a longer duration provided exercise intensity is low enough
Slow glycolysis
The enzyme that maintains the sarcolemmal concentration gradient after depolarization
Sodium-potassium ATPase
The direct resynthesis of ATP from ADP during a single reaction in the metabolic pathways
Substrate-level phosphorylation
Muscle that has not been desiccated
Wet muscle
The ratio of the time during internal training spent on the work and recovery portions of the exercise
Work-to-rest ratio
