Chapter 3 - Bioenergetics Flashcards
1
Q
Metabolic Specificity of Exercise and Training (3)
A
- Based on an understanding of the transfer of energy in biological systems.
- Efficient and productive training programs can be designed through an understanding of how energy is made available for specific types of exercise
- And how energy transfer can be modified by specific training regimens.
2
Q
Bioenergetics (4)
A
- The flow of energy in a biological system
- Concerns primarily the conversion of macronutrients into biologically usable forms of energy
- Macronutrients - carbs, protein, and fats - contain chemical energy
- It is the breakdown of the chemical bonds in these macronutrients that provides the energy necessary to perform biological work
3
Q
Catabolism (3)
A
- The breakdown of large molecules into smaller molecules
- Associated with the release of energy
- The breakdown of protein into amino acids is an example of catabolism
4
Q
Anabolism (4)
A
- The synthesis of larger molecules from smaller molecules
- Uses the energy released from catabolic reactions
- This is a building-up process
- The formation of protein from amino acids is an example of anabolic process
5
Q
Exergonic Reactions (2)
A
- Energy-releasing reactions
- Generally catabolic
6
Q
Endergonic Reactions (2)
A
- Requires energy
- Includes anabolic processes and the contraction of muscle
7
Q
Metabolism (1)
A
- The total of all the catabolic/exergonic and anabolic/endergonic reactions in a biological system
8
Q
Adenosine Triphosphate (ATP) (7)
A
- Classified as a high-energy molecule
- Because it stores large amounts of energy in the chemical bonds of the two terminal phosphate groups
- Allows the transfer of energy from exergonic to endergonic reactions
- Energy derived from catabolic/exergonic reactions is used to drive anabolic/endergonic reactions through this intermediate molecule, ATP
- Composed of Adenosine and 3 phosphate groups
- S&C professionals need to have a basic understanding of how exercise affects ATP hydrolysis and re-synthesis when designing training programs
- Because muscle cells store ATP only in limited amounts and activity requires a constant supply of ATP to provide the energy needed for muscle actions, ATP-producing processes must occur in the cell
9
Q
Adenosine (4)
A
- An organic compound
- The combination of adenine and ribose
- Adenine is a nitrogen-containing base
- Ribose is a five-carbon sugar
10
Q
Hydrolysis (3)
A
- The breakdown of one molecule of ATP to yield energy
- Because it requires one molecule of water
- The hydrolysis of ATP is catalyzed by the presence of an enzyme called ATPase - adenosine triphosphatase
11
Q
Adenosine Triphosphatase (ATPase)
A
- An enzyme
- The hydrolysis of ATP is catalyzed by the presence of this enzyme
12
Q
Myosin ATPase (1)
A
- An enzyme that catalyzes ATP hydrolysis for crossbridge recycling
13
Q
Calcium ATPase (2)
A
- Another specific enzyme that hydrolyzes ATP
- Pumps calcium into the sarcoplasmic reticulum
14
Q
Sodium-Potassium ATPase (2)
A
- Another specific enzyme that hydrolyzes ATP
- Maintains the sarcolemmal concentration gradient after depolarization
15
Q
What is this equation of? (6)
A
- Equation for ATP Hydrolysis
- The following equation depicts the reactants (left), enzyme (middle), and products (right)
- Reactants are Adenosine Triphosphate and Water molecule
- Enzyme is Adenosine Triphosphotase
- The products are Adenosine Diphosphate, Inorganic Phosphate, Hydrogen Ion (proton)
- The energy released primarily from the hydrolysis of ATP, and secondarily from ADP, results in biological work
16
Q
Adenosine Diphosphate (ADP)
A
- Only 2 phosphate groups
17
Q
Inorganic Phosphate (Pi)
A
- Molecule
18
Q
Adenosine Monophosphate (AMP)
A
- Further hydrolysis of ADP cleaves the second phosphate group and yields AMP
- Where cleaves means to divide
19
Q
3 Basic Energy Systems in Mammalian Muscle Cells to Replenish ATP
A
- Phosphagen System
- Glycolysis
- Oxidative System
- All 3 energy systems are active at any given time; however, the magnitude of the contribution of each system to overall work performance is primarily dependent on the intensity of the activity, and secondarily, on the duration
20
Q
Anaerobic Processes
A
- Does not require the presence of oxygen
21
Q
Aerobic Processes
A
- Depends on oxygen
22
Q
Phosphagen System
A
- Anaerobic mechanism
- Occurs in the sarcoplasm of a muscle cell
23
Q
Glycolytic Systems
A
- Anaerobic mechanism
- Occurs in the sarcoplasm of a muscle cell
24
Q
Krebs Cycle
A
- Aerobic mechanism
- Occurs in the mitochondria of muscle cells
- Requires oxygen as the terminal electron acceptor
25
Q
Oxidative System
A
- Aerobic mechanism
- Occurs in the mitochondria of muscle cells
- Requires oxygen as the terminal electron acceptor
26
Q
Mitochondria
A
- An organelle found in cells
- Double membrane structure
- Uses aerobic respiration to generate ATP
27
Q
Macronutrients
A
- Carbs, Protein, Fats
- Only Carbs can be metabolized for energy without the direct involvement of oxygen
- Therefore, carbohydrate is critical during anaerobic metabolism
28
Q
Phosphagen System
A
- Provides ATP primarily for short-term, high-intensity activities
- Is highly active at the start of all exercise regardless of intensity
- This energy system relies on the hydrolysis of ATP and breakdown of another high-energy phosphate molecule called creatine phosphate (CP)
- Because CP is stored in relatively small amounts, the phosphagen system cannot be the primary supplier of energy for continuous, long-duration activities
- Through CP and the creatine kinase reaction, this system serves as an energy reserve for rapidly replenishing ATP
29
Q
Creatine Phosphate (CP)
A
- A high-energy phosphate molecule
- Also called phosphocreatine (PCr)
- Suppkies a phosphate group that combines with ADP to replenish ATP
- Type II muscle fibers (fast-twitch) contain higher concentrations of CP than Type I (slow-twitch) fibers
30
Q
Creatine Kinase
A
- The enzyme that catalyzes the synthesis of ATP from CP and ADP
- This reaction provides energy at a high rate
- The phosphogan system uses the creatine kinase reaction to maintain the concentration of ATP
31
Q
Phosphocreatine (PCr)
A
- A high-energy phosphate molecule
- Also called creatine phosphate (CP)
32
Q
ATP Stores
A
- The body stores approx. 80 to 100g (about 3 oz) of ATP at any given time
- ATP stores cannot be completely depleted due to the necessity for basic cellular function
- ATP concentrations may decrease by up to 50% to 60% of the pre-exercise levels
33
Q
Adenylate Kinase Reaction
A
- A single-enzyme reaction that can rapidly replenish ATP
- Also called myokinase reaction
- AMP, a product of the adenylate kinase (myokinase) reaction, is a powerful stimulant to glycolysis
34
Q
Myokinase Reaction
A
- Also called adenylate kinase reaction
- A single-enzyme reaction that can rapidly replenish ATP
- AMP, a product of the adenylate kinase (myokinase) reaction, is a powerful stimulant to glycolysis
35
Q
Glycolysis
A
- The breakdown of carbohydrate- either glycogen store in the muscle or glucose delivered in the blood- to resynthesize ATP
- The process involves multiple enzymatically catalyzed reactions
- As a result, the ATP resynthesis rate during glycolysis is not as rapid as with the single-step phosphagen system
- However, the capacity to produce ATP is much higher due to a larger supply of glycogen and glucose compared to CP
- Occurs in the sarcoplasm
36
Q
Law of Mass Action
A
- The reactions of the phosphagen system are largely controlled by the law of mass action
- Also known as the mass action effect
- The concentrations of reactants or products (or both) in solution will drive the direction of the reactions
- With enzyme-mediated reactions, such as the reactions of the phosphagen system, the rate of product formation is greatly influenced by the concentrations of the reactants
37
Q
Pyruvate
A
- The end result of glycolysis
- Can be converted to lactate in the sarcoplasm
- Also can be shuttled into the mitochondria, to undergo the Krebs cycle
- The fat of pyruvate is ultimately controlled by the energy demands within the cell
- If energy demand is high and must be transferred quickly, as during resistance training, pyruvate is primarily converted to lactate for further support of anaerobic glycolysis
- If energy demand is not as high and oxygen is present in the cell, pyruvate can be further oxidized in the mitochondria
38
Q
Anaerobic Glycolysis
A
- When pyruvate is converted to lactate, ATP resynthesis occurs at a faster rate
- But is limited in duration due due to the subsequent H+ production and resulting decrease in cytosolic pH
- Also known as fast glycolysis
39
Q
Aerobic Glycolysis
A
- Also known as slow glycolysis
- When pyruvate is shuttled into the mitochondria to undergo the Krebs cycle, the ATP resynthesis rate is slower because of the numerous reactions
- But it can occur for a longer duration if exercise intensity is low enough
- However, because glycolysis itself does not depend on oxygen, the terms anaerobic and aerobic glycolysis are probably not practical
40
Q
Metabolic Acidosis
A
- The process of an exercise-induced decrease in pH
- May be responsible for much of the peripheral fatigue during exercise
41
Q
Gluconeogenesis
A
- The formation of glucose from noncarbohydrate sources - during extended exercise and recovery
42
Q
Wet Muscle
A
- Muscle that has not been desiccated
43
Q
Cori Cycles
A
- The process where lactate is transported in the blood to the liver, where it is converted to glucose
44
Q
Lactic Acidosis
A
45
Q
Nicotinamide Adenine Dinucleotide (NADH)
A
46
Q
Glycolysis Leading to the Krebs Cycle
A
47
Q
Two Primary Mechanisms for Re-synthesizing ATP
A
48
Q
Phosphorylation
A
49
Q
Oxidative Phosphorylation
A
50
Q
Electron Transport Chain (ETC)
A
51
Q
Substrate-Level Phosphorylation
A
52
Q
Phosphofructokinase (PFK)
A
53
Q
Glycogenolysis
A
54
Q
Control of Glycolysis
A
55
Q
Allosteric Inhibition
A
56
Q
Allosteric Activation
A
57
Q
Rate-Limiting Step
A
58
Q
Lactate Threshold (LT)
A
59
Q
Oxygen Uptake in Lactate Threshold
A
60
Q
Onset of Blood Lactate Accumulation (OBLA)
A
61
Q
The Oxidative (Aerobic) System
A
62
Q
Flavin Adenine Dinucleotide (FADH2)
A
63
Q
Cytochromes
A
64
Q
Fat Oxidation
A
65
Q
Fatty Acids & Beta Oxidation
A
66
Q
Protein Oxidation
A
67
Q
Branched-Chain Amino Acids
A
68
Q
Control of the Oxidative (Aerobic) System
A
69
Q
Substrate Depletion
A
70
Q
Repletion
A
71
Q
Rate of Glycogen Depletion
A
72
Q
Oxygen Uptake
A
73
Q
Oxygen Deficit
A
74
Q
Oxygen Debt
A
75
Q
Excess Post-Exercise Oxygen Consumption (EPOC)
A
76
Q
Aerobic Exercise and EPOC
A
77
Q
Resistance Exercise and EPOC
A
78
Q
Factors Responsible for EPOC
A
79
Q
Metabolic Specificity of Training
A
80
Q
Interval Training
A
81
Q
Work-to-Rest Ratios
A
82
Q
High-Intensity Interval Training (HIIT)
A
83
Q
9 HIIT Variables (to be manipulated)
A
84
Q
Combination Training
A
85
Q
Using Interval Training to Train Specific Energy Systems
A
86
Q
Lactic Acid
A
87
Q
Lactate
A
- Lactate is the product of the lactate dehydrogenase reaction
- Although the muscular fatigue experienced during exercise often correlates with high tissue concentrations of lactate, lactate is not the cause of fatigue
- Often used as an energy substrate, especially in Type I and cardiac muscle fibers
- It is also used in gluconeogenesis
- Normally, there is a low concentration of lactate in blood and muscle
- Normal range of lactate concentration in blood is 0.5 to 2.2 mmol/L at rest
- And 0.5 to 2.2 mmol for each kilogram of wet muscle
- Lactate production increases with exercise intensity
