Ch. 2 Bioenergetics of Exercise and Training Flashcards
bioenergetics
the flow of energy in a biological system, concerns primarily the conversion of macronutrients(carbs, proteins, and fats which contain chemical energy) into biologically usuable forms of energy
energy
the ability or capacity to perform work
the three basic systems that replenish ATP
the phosphagen system, glycolysis, the oxidative system
what powers muscular activity?
the energy stored in the chemical bonds of adenosine triphophate
phosphagen stystem
provides ATP primarily for short-term, high-intensity activites
What type of fibers have higher concentrations of Creatine Phosphate?
Type II, fast twitch
catabolism
the breakdown of large molecules into smaller molecules, associated with the release of energy
anabolism
the synthesis of larger molecules from smaller molecules, its accomplished using the energy from catabolic reactions
Exergonic reactions
energy releasing reactions
Endergonic reactions
require energy and include anabolic processes and the contraction of muscles
metabolism
the total of all the catabolic/exergonic and anabolic/endergonic reactions in a biological system
ATP (adenosine triphosphate)
an intermediate molecule, allows the transfer of energy from exergonic to endergonic reactions
hydrolysis
the breakdown of one molecule of ATP to yield energy
ATPase (adenosinetriphosphatase)
an enzyme that catalyzes the hydrolysis of ATP
myosin ATPase
the enzyme that catalyzes ATP hydrolysis for cross-bridge recycling
ADP (adenosine diphosphate)
2 phosphates
AMP (adenosine monophoshpate)
1 phosphate
anaerobic
processes that dont require oxygen
aerobic
processes that depend on oxygen
creatine phosphate (CP)
also known as phosphocreatine (PCr)
Creatine kinase
the enzyme that catalyzes the synthesis of ATP from CP and ADP
the adenylate kinase (or myokinase) reaction
an important single-enzyme reaction that can rapidly replenish ATP
law of mass action
states that the concentration of reactants or products in solution will drive the direction of the reactions
near-equilibrium reactions
proceed in a direction dictated by the concentrations of the reactants due to the law of mass actions
pyruvate
the end result of glycolysis, can be converted to lactate, can be shuttles into the mitochondria
anaerobic glycolysis (fast glycolysis)
process where pyruvate is converted to lactate, ATP resynthesizes as a faster rate, but is limited in duration
aerobic glycolysis (slow glycolysis)
when pyruvate is shuttled into the mitochondria to undergo the Krebs cycle, the ATP resythesizes slower, but can occur for a longer duration if the exercise intensity is low enough
lactate
comes from pyruvate, catalyzed by the enzyme lacate dehydrogenase
metabolic acidosis
the process of an exercise-induce decrease in pH
wet muscle
muscle that has not been desiccated
Cori cycle
the process by which lactate is transported in the blood to the liver, where it is converted to glucose
mitochondria
specialized cellular organelles where the reactions of aerobic metabolism occur
phosphorylation
the process of adding an inorganic phosphate to another molecule (ADP->ATP)
oxidative phosphorylation
the resynthesis of ATP in the electron transport chain
substrate level phosphorylation
describes the direct resynthesis of ATP from ADP during a single reaction in the metabolic pathways
Allosteric inhibition
occurs when an end product binds to the regulatory enzyme and decreases its turnover rate and slows product formation
allosteric activation
occurs when an “activator” binds with the enzyme and increases its turnover rate
lactate threshold (LT)
the exercise intensity or relative intensity at which blood lactate begins an abrupt increase above the baseline concentration
onset of blood lactate accumulation (OBLA)
the second increase in the rate of lactate accumulation has been noted at higher relative intensities of exercise
oxidative system
the primary source of ATP at rest and during low-intesnity activities, uses primarily carbs and fats as substrates
Krebs cycle
a series of reactions that continues the oxidation of the substrate begun in glycolysis and produces two ATP indireclty from guanine triphospahte via substrate-level phosphorylation for each molecule of glucose
electron transport chain (ETC)
uses NADH and FADH2 molecules to rephopsorylate ADP to ATP
beta oxidation
a series of reactions in which the free fatty acids are broken down, resulting in the formation of acetyl-CoA and hydrogen protons
branched-chain amino acids
(leucine, isoleucine, and valine) they are the major amino acids that are oxidized in skeletal muscle
exercise intensity
defined as a level of muscular activity that can be quantified in terms of power output
power
work performed per unit of time
energy substrates
molecules that provide starting materials for bioenergetic reactions, including phosphagens, glucose, glycogen, lactate, free fatty acids, and amino acids
phosphagens
ATP and creatine phosphate
glycogenolysis
the breakdown of glycogen
oxygen uptake
a measure of a person’s ability to take in and use oxygen
oxygen deficit
the anaerobic contribution to the total energy cost of exercise
oxygen debt (or excess postexercise oxygen consumption EPOC)
postexercise oxygen uptake
interval training
a method that emphasizes bioenergetic adaptions for a more efficient energy transfer within the metabolic pathways by using predetermined intervals of exercise and rest periods
combination training
cross-training, when aerobic endurance training is added to anaerobic training to enhance recovery because recovery relies primarily on aerobic mechanisms
