Bioenergetics Flashcards
bioenergetics
the flow of energy in a biological system, concerns primarily the conversion of macronutrients - which contain chemical energy into biologically usable forms of energy
catabolism
the breakdown of large molecules into smaller molecules, associated with the release of energy
anabolism
the synthesis of larger molecules from smaller molecules can be accomplished using eh energy released from catabolic reactions
exergonic reactions
energy releasing reactions
endergonic reactions
require energy and include the metabolic processes and the contraction of muscle
metabolism
the total of all the catabolic (exergonic) and anabolic (endergonic) reactions in a biological system
ATP
allows the transfer of energy from exergonic to endergonic reactions
hydrolysis
the breakdown of one molecule of ATP to yield energy
ATPase
the catalyst during hydrolysis of ATP
ADP
an inorganic phosphate molecule and hydrogen ions
anaerobic processes
do not require the presence of oxygen
aerobic processes
depend on oxygen
phosphogen and glycolytic systems
anaerobic mechanisms that occur in the sarcoplasm of the muscle cell
creatine phosphate and creatine kinase
breakdown of these phosphates are used in the phosphates system
law of mass action or the mass action effect
states that the concentrations of reactants or products (or both) in solution will drive the direction of reactions
glycolysis
the breakdown of carbohydrates - either glycogen stored in the muscle or glucose delivered in blood
pyruvate
the end result of glycolysis and my proceed in one of 2 directions -
- can be converted to lactate in the sarcoplasm
- can be shuttled into the mitochondria
anaerobic (fast) glycolysis
when the pyruvate is converted to lactate ATP resynthesis occurs at a faster rate via the rapid regeneration of NAD+, but is limited in duration due to the subsequent H+ production and resulting decrease in cytosolic pH
aerobic (slow) glycolysis
when the pyruvate is shuttled into the mitochondria to undergo the Krebs cycle, the ATP resynthesis rate is slower because of the numerous reactions, but can occur for longer duration if the exercise intensity is low enough
metabolic acidosis
the process of exercise induced decrease in pH
gluconeogenisis
the formation of glucose from non-carbohydrate sources
cori cycle
when lactate is transported in the blood to the liver where it is converted to glucose
phosphorylation
the process of adding an inorganic phosphate to another molecule - ATP is the phosphorylation of ADP to ATP
oxidative phosphorylation
the resynthesis of ATP in the electron transport chain
substrate-level phosphorylation
refers to the direct resythensis of ATP from ADP during a single reaction in the metabolic pathways
glycogenolysis
when muscle glycogen in the muscle is broken down into glucose
lactate threshold
when 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
