Final (Chapters 9-14) Flashcards
(84 cards)
1
Q
aerobic
A
Requires or uses oxygen.
2
Q
aerobic glycolysis
A
The complete breakdown of glucose or glycogen to water, carbon dioxide, and a net of either 36 or 37 ATP, respectively, in four stages (glycolysis, decarboxylation of pyruvate, Krebs cycle, ETS).
3
Q
anaerobic
A
Does not require or use oxygen.
4
Q
anaerobic glycolysis
A
The incomplete breakdown of a 6-carbon glucose (or G6P from the glycogenolysis of muscle glycogen) to two 3-carbon lactates in the cytoplasm of the cell, without the use of oxygen, yielding 2 or 3 net ATP, respectively.
5
Q
adenosine triphosphate
A
The primary energy molecule of the body. The hydrolysis of ATP is the only form of energy that can directly be used for muscle contraction and other cellular processes.
6
Q
beta oxidation
A
The cleaving of a 2-carbon unit from a long carbon chain fatty acid. Beta oxidation of a fatty acid in the mitochondria of the muscle cell.
7
Q
cellular respiration
A
All of the metabolic processes that use energy released from the breakdown of energy substrates to resynthesize ATP.
8
Q
deanimation
A
The removal of the nitrogen (NH2) from an amino acid. The nitrogen group (NH2) becomes ammonia (NH3) and is excreted from the body.
9
Q
endergonic reaction
A
An energy consuming reaction, for example the second reaction of the ATP-PC system.
10
Q
energy substrate
A
Foods (carbohydrates, fats, and proteins) that are used in metabolic pathways to resynthesize ATP.
11
Q
exergonic reaction
A
An energy releasing reaction, for example the first reaction of the ATP-PC system.
12
Q
gluconeogenesis
A
The formation of glucose in the liver from non-carbohydrate sources, such as lactate, glycerol, and amino acids.
13
Q
glycogen
A
The storage form of carbohydrate. Glycogen is formed by linking many glucose molecules together.
14
Q
glycogen loading
A
A 1 to 7 day process that increases the amount of glycogen in skeletal muscle, specifically skeletal muscle fibers that have been trained. Glycogen loading also increases liver glycogen, but to a lesser extent.
15
Q
glycogenesis
A
The formation of glycogen from many glucose molecules.
16
Q
glycogenolysis
A
The breakdown of glycogen to glucose. Glycogenolysis occurs in the liver and skeletal muscle.
17
Q
glycolysis
A
The breakdown of glucose to pyruvate in the cytoplasm of the cell.
18
Q
hydrolysis
A
A reaction in which water is used to break a chemical bond. The hydrolysis of ATP is an example in which the high-energy bonds linking the phosphate groups are broken.
19
Q
lipogenesis
A
The formation of triglyceride from fatty acids and glycerol.
20
Q
lipolysis
A
The breakdown of a triglyceride to three fatty acids and one glycerol.
21
Q
primary energy molecule
A
ATP is the primary energy molecule because the energy released from the hydrolysis of ATP is the only form of energy that can directly be used for muscle contraction and other cellular processes.
22
Q
transanimation
A
The transfer of the nitrogen-containing amino group to another molecule in order to form a new amino acid, pyruvic acid, acetyl CoA, or one of the Krebs cycle intermediates.
23
Q
triglycerides
A
The storage form of fat. Large amounts of triglycerides are stored in adipose tissue. Much smaller amounts of triglycerides are stored in skeletal muscle.
24
Q
aerobic glycolysis
A
The complete breakdown of glucose or glycogen to water, carbon dioxide, and a net of either 36 or 37 ATP, respectively, in four stages (glycolysis, decarboxylation of pyruvate, Krebs cycle, ETS).
25
anaerobic glycolysis
The incomplete breakdown of a 6-carbon glucose (or G6P from the glycogenolysis of muscle glycogen) to two 3-carbon lactates in the cytoplasm of the cell, without the use of oxygen, yielding 2 or 3 net ATP, respectively.
26
cell-to-cell lactate shuttle
The transport of lactate from the cytoplasm of the cell in which it is produced to the cytoplasm of a neighboring muscle cell.
27
FAD
Flavin adenine dinucleotide. A carrier molecule that transports hydrogens and electrons from one reaction to another in the cell.
28
glycolytic
A term refers to the use of anaerobic glycolysis. For example, type II muscle fibers are highly glycolytic because they are well suited for anaerobic glycolysis
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hexokinase
The enzyme that catalyzes the phosphorylation of glucose as it enters the skeletal muscle cell.
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intracellular lactate shuttle
The transport of lactate from the cytoplasm into the mitochondria of the same muscle cell by monocarboxylate transporters.
31
lactate dehydrogenase
The enzyme that catalyzes the reduction of pyruvate to lactate.
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lactate response curve
A plot of blood lactate values taken during every stage of an exercise test that incrementally increases in intensity from low intensity to maximal intensity.
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lactate threshold
The intensity of exercise at which there is a break in the linearity of the lactate response curve. The point in the curve that exhibits an exponential increase in blood lactate.
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maximal lactate steady-state
The highest intensity of aerobic exercise that results in less than a 1 mmol/L increase in blood lactate between minute 10 and minute 30 of a 30 minute exercise test at a constant workload.
35
NAD
Nicotinamide adenine dinucleotide. A carrier molecule that transports hydrogens and electrons from one reaction to another in the cell.
36
onset of blood lactate accumulation
A fixed blood lactate level (i.e., 4 mmol/L) that is sometimes used to define the lactate threshold.
37
oxidize
To accept oxygen or to lose hydrogens and/or electrons.
38
performance VO2
The VO2 at the highest intensity of aerobic exercise that can be maintained for a prolonged period of time without fatiguing due to the accumulation of lactate. Determined by multiplying VO2max by the percentage of VO2max at which the lactate threshold or maximal lactate steady-state occur.
39
phosphofructokinase
The rate limiting enzyme of glycolysis that catalyzes the phosphorylation of fructose-6-phosphate.
40
pyruvate dehydrogenase
The enzyme that catalyzes the oxidation and decarboxylation of pyruvate to acetyl-CoA.
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rate-limiting enzyme
The enzyme that catalyzes the reaction of the rate limiting step. The activity of the rate limiting enzyme is regulated, in part, by modulators within the cell such as the concentrations of ATP, ADP, and Pi.
42
reduce
To accept hydrogen and/or electrons or to lose oxygen.
43
beta oxidation
The cleaving of a 2-carbon unit from a long carbon chain fatty acid. Beta oxidation of a fatty acid in the mitochondria of the muscle cell.
44
catecholamines
Norepinephrine and epinephrine secreted by the adrenal medulla.
45
cortisol
A hormone released by the adrenal cortex that stimulates lipolysis in adipose tissue, glycogenolysis and gluconeogenesis in the liver, the breakdown of proteins, and retards the entry of blood glucose into the muscle cell. The overall effect of increased cortisol levels during exercise is an increase in blood glucose levels and an increase in fat utilization.
46
fatty acid
One of the end-products of lipolysis of a triglyceride. The fatty acid enters the mitochondria of the muscle cell where it undergoes beta oxidation.
47
glucagon
A hormone secreted by the pancreas that has opposing effect to those of insulin. The increase in glucagon during exercise stimulates glycogenolysis in the liver and lipolysis in adipose tissue.
48
glycerol
One of the end-products of lipolysis of a triglyceride. Although glycerol can enter glycolysis, most of the glycerol in converted to glucose in the liver in a process called gluconeogenesis.
49
growth hormone
A hormone secreted by the anterior pituitary that plays a major role in the synthesis of tissue protein by increasing the uptake of amino acids. Growth hormone also stimulates gluconeogenesis and lipolysis and retards the entry of blood glucose into the muscle cell. The overall effect of increased growth hormone secretion during exercise is increased availability of fatty acids and maintenance of blood glucose.
50
insulin
A hormone released from the pancreas that stimulates the storage of carbohydrates (glycogenesis) by initiating a series of reactions that translocate GLUT 4 to the cell membrane and increase the entry of blood glucose into the cell. Insulin inhibits glycogenolysis, gluconeogenesis, and lipolysis.
51
lipolysis
The breakdown of a triglyceride to three fatty acids and one glycerol.
52
modulators
Substances that increase or decrease the activity of an enzyme. Intracellular modulators include the concentration of ATP, ADP, and Pi.
53
triglycerides
The storage form of fat. Large amounts of triglycerides are stored in adipose tissue. Much smaller amounts of triglycerides are stored in skeletal muscle.
54
dehydration
Abnormally low levels of hydration. Hydration status is generally determined by urine color or measurement of urine specific gravity.
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fatigue
The inability to maintain a given intensity of exercise.
56
hypoglycemia
Low blood glucose levels. A normal fasting blood glucose level is about 100 mg/dL. Hypoglycemia is sometimes defined as a blood glucose level below 50 mg/dL.
57
predominant energy system
The one metabolic pathways that most closely matches the energy demands of the body at a given time. The energy demands of the body, and therefore the predominant energy system, are determined primarily by the intensity and duration of the exercise. Other factors such as timing and composition of meals and training status also contribute to the predominant energy system.
58
active recovery
The concept of exercising at a low intensity during the recovery period following exercise. An active recovery is the opposite of a "resting recovery". An active recovery helps maintain blood flow during the recovery period which helps facilitate the removal of lactate and assist with the dissipation of heat.
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caloric equivalent
The number of calories expended per liter of oxygen consumed (kcal/L). The caloric equivalent is determined by the RER. An estimate of the caloric equivalent is 5 kcal/L.
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compendium of physical activities
A collection, or compilation of information regarding the MET values for a variety of different physical activities.
61
Cori cycle
The metabolic pathway that involves lactate produced in skeletal muscle entering the blood and being transported to the liver where it undergoes gluconeogenesis and is converted to glucose. The glucose then re-enters the blood and is transported and used throughout the body, including in the same muscle in which the lactate was produced.
62
crossover concept
The concept that as intensity of aerobic exercise increases, the relative contribution of carbohydrates to the total energy demands increases and the relative contribution of fats to the total energy demands decreases. At an intensity of exercise below the crossover, a greater percentage of the energy demand is met by fat metabolism. At an intensity of exercise above the crossover, a greater percentage of the energy demand is met by carbohydrate metabolism.
63
excess post-exercise oxygen consumption (EPOC)
The time period following the cessation of exercise during which oxygen consumption and energy expenditure are above resting values. The duration of EPOC is a function of the overall physiological stress of the preceding exercise (intensity, duration, hydration status, lactate accumulation, thermal stress, etc.).
64
indirect calorimetry
The measurement of VO2 at rest or during exercise which can then be used to calculate energy expenditure.
65
MET-minutes
The MET value of an activity multiplied by the amount of time (minutes) actually spent doing the activity. For example, if Joe exercises for 30 minutes at an intensity equivalent to 5 METs then he has accrued 150 MET-minutes (5 METs x 30 min). The recommended amount of physical activity is roughly equal to accruing 500 - 1000 MET-minutes per week.
66
metabolic equivalent (MET)
1 MET is an estimate of the amount of energy expended at rest. Multiples of a MET can be used to define the intensity of exercise. For example, an intensity of exercise that is equivalent to 10 METs is 10 times more metabolically demanding than resting. Although METs are used to define intensity of exercise (light = 1.1 - 2.9 METs; moderate = 3.0 - 5.9 METs; vigorous = >6 METs) it is an absolute definition of intensity that does not take into consideration the fitness level of the individual. For example, although exercising at an intensity equivalent to 8 METs is defined as "vigorous," it may seem relatively easy to a person that has a high fitness level.
67
MFO
Maximal rate of fat oxidation. The rate of fat oxidation is expressed in absolute terms (grams/min) rather than in relative terms (percentage). As the intensity of aerobic exercise increases, the absolute amount of fat that is used increases, to a point, which is the MFO. At intensities of exercise above the MFO, there is a sharp decrease in the absolute amount of fat that is being used.
68
oxygen deficit
A time period during which the metabolic (energy) demands of the body cannot be met by aerobic metabolic pathways. During periods of oxygen deficit, anaerobic metabolic pathways make up the difference between the energy demand of the exercise and the energy that can be provided by aerobic pathways.
69
priming
Prior high-intensity exercise that is meant to "prime the muscle" or in other words, prepare the muscle for use in the specific type of exercise that will follow. Priming differs from "warming up" in that warming up generally refers to a variety of low- to moderate-intensity activities that precede an exercise session.
70
rating of perceived exertion (RPE)
A 0-10 point or a 6-20 point numerical scale anchored with adjectives (e.g., very light, light, hard, very hard, etc.) that describe the perceived difficulty of the exercise.
71
respiratory exchange ratio (RER)
The ratio of VCO2/VO2. A RER = 1.0 indicates that only carbohydrates are being utilized. An RER = 0.7 indicates that only fats are being utilized. The RER is used to determine the caloric equivalent and the contribution of fats and carbohydrates to the total energy expended at rest or during exercise. Use of the RER to calculate energy expenditure assumes a steady-state condition and negligible contribution of anaerobic pathways and protein.
72
steady-state
A period of time during which the metabolic demands are constant and aerobic metabolic pathways meet most of the energy demands of the exercise. Steady-state conditions occur at rest and during submaximal intensities of exercise.
73
VO2 slow component
The upward trend in VO2 after the first several minutes of exercise when a plateau (steady-state) would otherwise be expected. The VO2 slow component is a result of starting exercise at an intensity that is too high to achieve a steady-state. Starting exercise at an intensity of exercise above the lactate threshold results in the VO2 slow component.
74
carbohydrate loading
A 1- to 7-day dietary and exercise process that stimulates increases storage of carbohydrates in trained skeletal muscle. Carbohydrate loading is typically recommended when the duration of exercise is greater than 90 minutes.
75
energy availability (EA)
A concept used to determine the adequacy of caloric intake to meet the energy demands of exercise as well as the all the normal bodily functions. Energy availability (EA) is calculated as energy intake (EI) minus energy expenditure (EE) during exercise (EA = EI - EE). The EA is the amount of calories available to the body for other functions after the energy cost of the exercise is accounted for. The EA is expressed as kcal/kg fat free mass/d. The threshold for EA below which risk and severity of consequences increases in 30 kcal/kg FFM/d/.
76
hyponatremia
A disorder in the fluid-electrolyte balance that results in an abnormally low plasma sodium concentration. During exercise, hyponatremia is typically a result of consuming a large amount of water and not replacing the electrolytes lost during exercise.
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negative nitrogen balance
Negative nitrogen balance is when nitrogen intake < nitrogen excretion.
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nitrogen balance
A measure of the balance between protein (nitrogen) consumption and nitrogen excretion. Nitrogen balance is when nitrogen intake = nitrogen excretion.
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personal hydration plan
An individualized plan for fluid and carbohydrate consumption during exercise. The fluid and carbohydrate needs during exercise are determined primarily from the duration of the exercise. The personal hydration plan is calculated using information recorded in a training journal.
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positive nitrogen balance
Negative nitrogen balance is when nitrogen intake > nitrogen excretion.
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pre-game meal
The high carbohydrate meal (3-5 grams of carbohydrate/kg; 150-300 g of carbohydrate) that is consumed 3-4 hours prior to exercise. The purpose of the pre-game meals is to "top off" muscle and liver glycogen stores prior to exercise.
82
sports drink
A carbohydrate drink formulated to be consumed during exercise. Typically contains 4-8% carbohydrate (4-8 g carbohydrate per deciliter), potassium, and sodium.
83
urine color chart
A color chart used to assess hydration status based on the color of the urine. A clear to pale yellow, or a 0, 1, 2, 3 on the color chart is considered normal hydration.
84
urine specific gravity (USG)
A parameter measured from a urine sample. One of the functions of the kidney is to dispose of water soluble waste molecules by excreting the molecules in the urine. The concentration of the excreted molecules in the urine determines the urine's specific gravity. A well hydrated individual will have a USG < 1.010.
