Bioenergetics and Metabolism W2 Flashcards
What is bioenergetics?
Flow and exchange of energy within a living system
Conversion of food into usable energy for cell work
“Chemical to Mechanical”
What is the cell membrane (sarcolemma)?
Semipermeable membrane that separates the cell from the extracellular environment
What is the nucleus?
Contains genes that regulate protein synthesis
What is the cytoplasm (sarcoplasm)?
Fluid portion of cell
Contains organelles
What is the mitochondria?
Location of oxidative phosphorylation
What is metabolism?
Sum of all chemical reactions that occur in the body
What is an anabolic reaction?
Synthesis of molecules
What is an catabolic reaction?
Breakdown of molecules
What is an endergonic reaction?
It requires energy to be added to the reactants
Glycogen Formation
What is an exergonic reaction?
Releases energy
ATP hydrolysis
What is a coupled reaction?
Liberation of energy in an exergonic reaction drives an endergonic reaction
What is reduction?
Addition of an electron
What is oxidation?
Removing an electron
What are enzymes?
Proteins that lower the energy of activation and accelerate chemical reaction
Increases rate of product formation
What is a kinase?
Add a phosphate group
What is a dehydrogenase?
Remove hydrogen atoms
What is a oxidase?
Catalyse oxidation-reduction reactions involving oxygen
What is a isomerase?
Rearrangement of the structure of molecules
What is the anaerobic pathway?
Does not involve oxygen
Phosphocreatine breakdown and glycolysis
What is the aerobic pathway?
Requires oxygen
Oxidative phosphorylation
Dependent on respiratory and cardiovascular systems to deliver adequate O2
What is glycogen phosphorylated by in glycolysis?
Inorganic phosphate
What is needed for chemical reactions in glycolysis to continue?
Adequate amounts of NAD+ must be available to accept H+
How is NAD+ rapidly reformed from NADH?
(2 ways)
1) Sufficient O2= H+ can be shuttled into mitochondria for ATP generation (aerobic)
2) Absence of O2= Pyruvate accepts hydrogens to from lactate (anaerobic) (lactate dehydrogenase)
What does the citric acid cycle do?
Completes oxidation of acetyl-CoA to provide electrons for the electron transport chain
What does the electron transport chain do?
Energy obtained from electron transport is used to produce ATP at the end of the electron transport chain
What are rate limiting enzymes?
1) Are found early in a metabolic pathway
2) Activity is regulated by modulators
What is the resting O2 consumption?
0.25 L.min
What is oxygen deficit?
Discrepancy between initial demand/ ATP production and oxygen consumption
Why do endurance trained individuals have a lower O2 deficit than untrained?
They have developed bioenergetic capacity
They have increased mitochondrial volume in muscle fibres
What does greater aerobic bioenergetic capacity do?
It has greater regional bloody flow to active muscle
It has increased cellular adaptation and efficiency
What is the 1st law of thermodynamics?
Energy cannot be created or destroyed,, only transformed from 1 form to another
What is the rate limiting-enzyme of the ATP-PC system?
Creatine kinase
What is the rate limiting-enzyme of glycolysis?
Phosphofructokinase
What is the rate limiting-enzyme of the citric acid cycle?
Isocitrate dehyrdrogenase
What is the rate limiting-enzyme of the electron transport chain?
Cytochrome oxidase
What inhibits the ATP-PC system?
ATP
What inhibits glycolysis?
ATP
CP
Citrate
pH
What inhibits the citric acid cycle?
ATP
NADH
What inhibits the electron transport chain?
ATP
What is EPOC?
Excessive post-exercise oxygen consumption (EPOC)
Reflects that only around 20% elevated O2 consumption used to repay O2 deficit
What is magnitude and duration of EPOC influenced by?
The intensity of exercise
What does the rapid portion of EPOC cause?
Re-synthesis of stored in muscle (completely recovered in 60-120s)
Replenishing muscle (myoglobin) and blood (hemoglobin) O2 stores
What does the slow portion of EPOC cause?
Elevated heart rate and breathing increase O2 demand
Elevated body temperature= increased metabolic rate
Elevated blood levels of epinephrine and norepinephrine= increases metabolic rate
Conversion of lactic acid to glucose
What is gluconeogenesis?
The biosynthesis of glucose from non-carbon products
