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