Chapter 3: Energy Systems and Exercise Flashcards
Creatine phosphate (CrP)
organic compound that stores potential energy in its phosphate bonds, stored in muscles and other tissues
Characteristics of creatine phosphate system (ATP-PC)
- one chemical step
- catalyzed by creatine kinase
- very fast reaction
- one ATP per CrP molecule
- 5-10 second duration
- Anaerobic
- Fatigue associated with CrP depletion
- Predominant energy system in very high intensity exercise, ‘power’ events
Creatine
- consumed in the diet and synthesized by amino acids
- sources in diet fish and beef
- 1/3 stored in muscle. 2/3 as creatine phosphate
- excretion is approximately 2/g per day
- vegetarians have less in muscle in than meat eaters
Characteristics of anaerobic glycolysis
- 18 chemical steps/reactions, 6 are repeated
- 12 chemical compounds, 11 enzymes
- rate-limiting enzyme, phosphofructokinase (PFK)
- fast but not as fast as ATP-PC
- Two ATP produced via glucose, 3 ATP produced via glycogen
- Anerobic
- 1-2 minute duration
- fatigue associated with decreased PH
- sustained repeated sprints, 400 m sprint
Glycogenolysis
metabolic breakdown of glycogen
glycolysis
metabolic breakdown of glucose
Metabolic acidosis
Decrease in PH associated with high intensity exercise and the use of the anerobic glycolysis energy system
Lactate
the metabolic end product of glycolysis
- lactate is metabolized aerobically
- converted to pyruvate
- in the liver, converted to glucose by the cori cycle
Pyruvate
chemical compound that is an important intermediate of glycolysis
Rate-limiting enzyme
in a series of chemical reactions, the enzyme that influences the rate of the entire series of reactions by changes in its activity
Lactate Threshold
- Point of sudden increase in blood lactate concentration
• Mistakenly called Anaerobic Threshold(AT)
• Lactate production outpaces lactate removal mechanisms
oxidative phosphorylation
the aerobic energy system
1st phase of oxidate phosphorylation
takes place in the mitochondria, carbs, fats, and proteins are prepared to be metabolized aerobically
Krebs cycle
series of oxidation-reduction reactions used to metabolize carbohydrates, fats, and proteins
electron transport phase
a series of electron-passing reactions that provides energy for ATP formation
Characteristics of oxidative phosphorylation
- 124 chemical steps/reactions
- 30 compounds, 27 enzymes
- rate-limiting enzymes: PFK, IDH, COX
- slow
- 30 ATP via glucose, 31 via glycogen
- potentially limitless duration
- aerobic
- fatigue associated with fuel depletion
- predominant energy system in endurance exercise
oxidation
giving up electrons
reduction
accepting electrons
Creatine supplementation
allows strength and power athletes to sustain high-intesnsity training
the preferred energy source by exercising muscle for the process of aerobic glycolysis
glycogen
how does the amount of ATP produced from the breakdown of one molecule of carbohydrate compare to the breakdown of one molecule of a fatty acid
the amount by fat is about 3.5 times greater
respiratory exchange ratio (RER)
ratio of carbon dioxide production to oxygen consumption; used to determine percentage of fats and carbs used for metabolism
beta-oxidation
chemical process of breaking down fatty acid chains for aerobic metabolism
fed-fast state
depends on the utilization of substrates, influences metaabolism
oxygen deficit
the lag in oxygen consumption at the onset of exercise
oxygen debt or excess post exercise oxygen consumption
the elevated oxygen consumption that occurs for a short time during the recovery period after an exercise bout has ended
average oxygen consumption
3.5 ml/kg/min
fuel utilization of carbs
metabolized in oxidative phosphorylation (glucose or glycogen)
fuel utilization of fats
metabolized aerobically by the oxidation of fatty acids
fuel utilization of proteins
metabolized aerobically by the oxidation of amino acids
lypolysis
term used for the breakdown of triglycerides
