Bioenergetics And Exercise Metabolism Flashcards
What is biogenetics
Flow and exchange of energy within a living system
Conversion of foods into usable energy for cell work
What is metabolism
Sum of all chemical reactions that occur in the body
What are anabolic reactions
Synthesis of molecules
What are catabolic reactions
Breakdown of molecules
Cellular chemical reactions:
Energy cannot be created or destroyed only transformed from one to another.
Endergonic: requires energy to be added to the reaction
Exergonic: releases energy
What is a coupled reaction
Liberation of energy in an Exergonic reaction drives an endergonic reaction
What is oxidation and reduction
Oxidation: removing an electron
Reduction:adding an electron
What are enzymes
They are proteins that lower the energy of activation and accelerate chemical reactions
How enzymes lower the energy of activation
1.Kinase: add a phosphate group
2.dehydrogenase: removal of hydrogen atoms
3.oxdiases: catalayzes oxidation reduction reactions involving oxygen
4.isomerases: rearrangement of the structure of molecules
Describe anaerobic pathways
- Does not involve oxygen
2.phophocreatine breakdown and glycolysis
Describe aerobic pathways
1.requires oxygen
2.oxidative phosphorylation
3.dependant on cardiovascular system and respiratory systems to provide oxygen
Describe atp-pc system
Most rapid and simplest (one enzyme reaction) method of producing atp by phosphocreatine breakdown.
It has a limited capacity to produce energy, depleted after 10-15 seconds of all out activity
Describe glycolysis
1.increases in the by products of atp that activates energy flux through reactions of glycoytix pathways
2.three fold higher than atp-pc system about 30-90 seconds.
What needs to be available for glycolysis to continue
Adequate amounts of nad must be available to accept hydrogen
Describe how NADH is formed
- If sufficient oxygen is available hydrogen can be shuttled into mitochondria for atp production
2.in the absence of oxygen, pyruvate can accept the hydrogens to form lactate
What is the Krebs cycle
Completed oxidation of acetyl coa to provide electrons for the electron transports chain
Describe how the Krebs cycle works
1.glycolysis generates 2 molecules of pyruvate
2.pyruvic acid enters the mitochondria and is converted to acetyl coa losing a carbon
3.acetyl coa combines with oxaloacetate to form citrate
4.series of reactions to generate oxaloacetate
5.each turn of the cycle, 1 atp molecule is synthesized from guanosine triphosphate with the release of high energy electrons
What are rate limiting enzymes
1.found early in a metabolic pathway
2.activity is regulated by modulators
What are the energy requirements at rest
1.almost 100% of atp produced by aerobic metabolism
2.blood lactate levels are low
Describe rest to exercise transitions
1.ATP production increases immediately.
2.oxygen uptake rapidly increases
3. Initial atp production must be through anaerobic pathways which creates an oxygen deficit
Why do endurance trained individuals have a lower oxygen deficit than untrained
1.better developed aerobic boienergetic capacity:
Greater regional blood flow to active muscle
2.increase mitochondrial volume in muscle fibres results in less lactate production at the beginning of exercise
Excess post exercise oxygen consumption:
EPOC was coined to replace the term ‘oxygen debt’
What is the rapid portion of EPOC
- Resynthesis of stored PC in muscle
2.replenishing muscle and blood oxygen stores
What is the slow portion of EPOC
1.elevated heart rate and breathing increases oxygen demand
2.elevated body temp=increased metabolic rate
3.elevated blood levels of epinephrine and norepinephrine = increased metabolic rate
4.conversion of lactic acid to glucose
