exercise2 Flashcards
(150 cards)
1
Q
What is gene expression?
A
“The process by which information from a gene is used to create functional proteins.”
2
Q
What are the main steps of gene expression?
A
“Transcription and translation.”
3
Q
What enzyme is responsible for transcription?
A
“RNA polymerase.”
4
Q
Where does transcription occur in eukaryotic cells?
A
“In the nucleus.”
5
Q
What is the function of mRNA?
A
“To carry genetic information from DNA to ribosomes for protein synthesis.”
6
Q
What is the role of ribosomes in gene expression?
A
“They translate mRNA into proteins.”
7
Q
What is a transcription factor?
A
“A protein that regulates gene expression by binding to DNA.”
8
Q
How do transcription factors influence gene expression?
A
“They activate or repress transcription of specific genes.”
9
Q
What is epigenetics?
A
“The study of heritable changes in gene function that do not involve DNA sequence changes.”
10
Q
How does DNA methylation affect gene expression?
A
“It typically suppresses gene transcription.”
11
Q
What is histone acetylation?
A
“A process that enhances gene expression by loosening chromatin structure.”
12
Q
What is the function of microRNAs (miRNAs)?
A
“They regulate gene expression by degrading mRNA or inhibiting translation.”
13
Q
What is the role of the mTOR pathway in muscle growth?
A
“It regulates protein synthesis and cell growth.”
14
Q
How does exercise influence gene expression?
A
“It activates pathways that enhance mitochondrial function and protein synthesis.”
15
Q
What is PGC-1α, and why is it important?
A
“A key regulator of mitochondrial biogenesis and oxidative metabolism.”
16
Q
How does resistance exercise affect gene expression?
A
“It increases the expression of genes involved in muscle hypertrophy.”
17
Q
What signaling pathway is crucial for endurance training adaptations?
A
“AMPK pathway.”
18
Q
What is hypoxia-inducible factor-1α (HIF-1α)?
A
“A protein that regulates gene expression in response to low oxygen levels.”
19
Q
How does endurance training affect mitochondrial gene expression?
A
“It upregulates genes involved in oxidative metabolism.”
20
Q
What is the function of nuclear receptors?
A
“They regulate gene expression in response to steroid and thyroid hormones.”
21
Q
How does insulin signaling influence muscle growth?
A
“It activates the Akt/mTOR pathway to promote protein synthesis.”
22
Q
What is the JAK-STAT signaling pathway?
A
“A pathway involved in cytokine signaling and immune responses.”
23
Q
What is the effect of endurance training on GLUT4 expression?
A
“It increases GLUT4 expression, improving glucose uptake.”
24
Q
How does calcium signaling influence muscle adaptation?
A
“It activates transcription factors that regulate muscle plasticity.”
25
What is chromatin remodeling?
"The modification of chromatin structure to regulate gene expression."
26
How does oxidative stress affect gene expression?
"It can activate transcription factors like NRF2 for antioxidant defense."
27
What is autophagy, and how is it regulated?
"The process of cellular degradation regulated by the AMPK pathway."
28
What is the function of FOXO transcription factors?
"They regulate genes involved in muscle atrophy and metabolism."
29
How does AMPK signaling respond to energy demand?
"It promotes catabolic pathways and inhibits anabolism during low energy states."
30
What is the role of cytokines in exercise-induced gene expression?
"They mediate communication between cells and regulate inflammation and adaptation."
31
What is hypoxia?
"A condition where oxygen availability is reduced in tissues."
32
What are the main types of hypoxia?
"Hypoxic, anemic, stagnant and histotoxic hypoxia."
33
What causes hypoxic hypoxia?
"Low oxygen availability, such as at high altitudes."
34
How does altitude affect barometric pressure?
"Barometric pressure decreases with altitude, lowering oxygen availability."
35
At what altitude does arterial oxygen saturation start to decline significantly?
"Above 3 000 meters."
36
Why does VO2 max decrease at high altitude?
"Reduced oxygen availability limits aerobic metabolism."
37
What are the immediate physiological responses to acute hypoxia?
"Increased ventilation, increased heart rate and increased cardiac output."
38
What is the role of peripheral chemoreceptors in hypoxia?
"They detect low oxygen levels and stimulate ventilation."
39
How does the oxygen-hemoglobin dissociation curve shift in acute hypoxia?
"It shifts left, increasing hemoglobin’s affinity for oxygen."
40
What are the symptoms of acute mountain sickness (AMS)?
"Headache, nausea, dizziness and fatigue."
41
How does chronic hypoxia affect erythropoiesis?
"Increases erythropoietin (EPO) production, stimulating red blood cell formation."
42
What adaptation occurs in hemoglobin levels with chronic altitude exposure?
"Hemoglobin concentration increases to improve oxygen transport."
43
How does the oxygen-hemoglobin dissociation curve shift with acclimatization?
"It shifts right due to increased 2,3-DPG enhancing oxygen unloading in tissues."
44
What is the primary long-term adaptation to high altitude?
"Increased red blood cell production and capillarization."
45
How does chronic hypoxia affect capillary density?
"Increases capillarization to improve oxygen delivery."
46
What is high-altitude pulmonary edema (HAPE)?
"Fluid accumulation in the lungs due to excessive pulmonary artery pressure."
47
What is high-altitude cerebral edema (HACE)?
"Swelling of the brain due to hypoxia-induced fluid leakage."
48
How does hypoxia affect exercise performance?
"Reduces aerobic capacity and endurance due to lower oxygen availability."
49
How does the body maintain oxygen delivery during hypoxia?
"Increases ventilation, cardiac output and hemoglobin concentration."
50
What hormone is primarily responsible for altitude-induced red blood cell production?
"Erythropoietin (EPO)."
51
What is hypoxic ventilatory response (HVR)?
"The increase in ventilation due to low oxygen levels."
52
How does hypoxia affect pulmonary vasculature?
"Causes vasoconstriction, increasing pulmonary artery pressure."
53
What happens to muscle oxygen utilization during hypoxia?
"It decreases due to limited oxygen availability."
54
What training method simulates hypoxia to improve performance?
"Live high train low (LHTL)."
55
Why does ventilation remain elevated after prolonged exposure to altitude?
"To compensate for lower oxygen levels in the air."
56
How does high-altitude acclimatization affect acid-base balance?
"Increased bicarbonate excretion helps regulate blood pH."
57
What is the main advantage of living at high altitude for endurance athletes?
"Increased red blood cell count improves oxygen transport."
58
What is the role of hypoxia-inducible factor-1α (HIF-1α)?
"It regulates gene expression for oxygen homeostasis and angiogenesis."
59
How does hypoxia influence mitochondrial function?
"Reduces mitochondrial efficiency and ATP production."
60
What is normobaric hypoxia?
"Reduced oxygen availability at sea level by altering oxygen concentration in the air."
61
What are the two main types of exercise training adaptations?
Endurance training and resistance training
62
How does endurance training affect VO2 max?
It increases VO2 max by improving oxygen delivery and utilization.
63
What limits VO2 max improvements in highly trained individuals?
Cardiac output and oxygen delivery capacity.
64
How does endurance training impact lactate threshold?
It raises the lactate threshold, allowing for higher intensity exercise before fatigue.
65
What are the key circulatory adaptations to endurance training?
Increased stroke volume, cardiac output, and capillarization.
66
How does endurance training affect mitochondrial function?
It increases mitochondrial density and oxidative enzyme activity.
67
What happens to resting heart rate after endurance training?
It decreases due to increased stroke volume and parasympathetic activity.
68
How does resistance training improve muscle strength?
Through neural adaptations and muscle hypertrophy.
69
What are the two phases of strength adaptation in resistance training?
Neural adaptations (early phase) and hypertrophy (later phase).
70
How does resistance training affect muscle fiber types?
It increases the size of type I and type II fibers, especially type II.
71
How does resistance training affect tendon and ligament strength?
It increases collagen synthesis, improving structural integrity.
72
What is muscle hypertrophy?
The increase in muscle fiber size due to resistance training.
73
What signaling pathway is crucial for muscle hypertrophy?
The mTOR pathway.
74
How does training affect insulin sensitivity?
Improves glucose uptake by increasing GLUT4 expression.
75
What is the impact of endurance training on muscle glycogen storage?
It increases glycogen storage capacity.
76
How does high-intensity interval training (HIIT) improve endurance?
By increasing VO2 max, mitochondrial function, and lactate threshold.
77
What is the primary adaptation of the heart to endurance training?
Increased stroke volume and heart chamber size.
78
How does endurance training affect fat metabolism?
It increases fat oxidation, reducing glycogen reliance.
79
What is supercompensation in exercise training?
The body's enhanced adaptation following recovery from training.
80
How does training improve muscle capillarization?
By increasing blood vessel growth (angiogenesis).
81
How does aerobic training affect cardiac output?
Increases it by improving stroke volume and oxygen delivery.
82
How does endurance training impact respiratory efficiency?
It improves oxygen uptake and utilization in the lungs.
83
What adaptation allows endurance-trained muscles to use more oxygen?
Increased myoglobin concentration.
84
What is the primary muscular adaptation to resistance training?
Increased muscle fiber size and contractile protein content.
85
How does resistance training affect motor unit recruitment?
It enhances neural activation, improving force generation.
86
What is the role of satellite cells in muscle adaptation?
They help repair and grow muscle fibers after resistance training.
87
How does resistance training affect muscle endurance?
It increases resistance to fatigue in trained muscles.
88
How does training volume influence hypertrophy?
Higher volume training leads to greater hypertrophy.
89
What is concurrent training, and how does it affect adaptations?
Combining endurance and resistance training; may limit hypertrophy.
90
How does endurance training affect oxidative enzymes?
It increases oxidative enzyme activity, enhancing aerobic metabolism.
91
What are the three primary ATP production pathways in skeletal muscle?
Creatine kinase system, glycolysis, oxidative phosphorylation
92
Which energy system provides immediate ATP for muscle contraction?
Creatine phosphate system
93
Why does carbohydrate oxidation dominate during high-intensity exercise?
It produces ATP faster and requires less oxygen than fat oxidation
94
What is VO2 max?
Maximum oxygen uptake, an indicator of aerobic capacity
95
How does exercise intensity affect fuel selection?
Higher intensity uses carbohydrates; lower intensity favors fat oxidation
96
What is the respiratory exchange ratio (RER)?
The ratio of CO2 produced to O2 consumed, indicating fuel utilization
97
Why is oxygen consumption elevated after exercise (EPOC)?
To restore ATP, remove lactate, and replenish oxygen stores
98
How does prolonged exercise affect blood glucose levels?
It decreases due to increased muscle glucose uptake
99
What is the main determinant of endurance performance?
VO2 max and lactate threshold
100
How does endurance training affect blood lactate levels?
It reduces lactate accumulation at submaximal intensities
101
What happens to insulin levels during prolonged exercise?
They decrease to promote fat oxidation and glucose sparing
102
Why does blood flow to muscles increase during exercise?
To deliver oxygen and remove metabolic waste
103
What is lactate threshold?
The exercise intensity at which lactate accumulates in the blood
104
What is the role of epinephrine during exercise?
Stimulates glycogenolysis and fat breakdown
105
How does resistance training impact metabolic rate?
Increases resting metabolic rate due to muscle hypertrophy
106
What limits performance in high-intensity, short-duration exercise?
ATP depletion and lactate accumulation
107
What limits performance in prolonged endurance exercise?
Glycogen depletion and dehydration
108
How does training affect stroke volume?
Increases due to enhanced cardiac efficiency
109
How does exercise impact mitochondrial density?
Endurance training increases mitochondrial density for ATP production
110
Why does muscle glycogen depletion lead to fatigue?
It reduces ATP availability and impairs muscle function
111
How does aerobic training affect oxygen delivery?
Increases capillarization and red blood cell mass
112
What is the function of myoglobin in muscle?
Stores oxygen and facilitates oxygen transport within muscle cells
113
How does training intensity affect fat oxidation?
Low-intensity exercise relies more on fat oxidation than high intensity
114
What role does hemoglobin play in exercise?
Transports oxygen from the lungs to the muscles
115
How does dehydration affect exercise performance?
Reduces blood volume, increases heart rate, and impairs thermoregulation
116
Why does cardiac output increase during exercise?
To supply more oxygen and nutrients to working muscles
117
What is the primary energy source for short bursts of maximal effort?
ATP-CP system (Creatine phosphate system)
118
How does high-intensity interval training (HIIT) improve endurance?
Increases VO2 max, lactate threshold, and mitochondrial function
119
How does endurance training affect heart rate recovery?
Improves recovery by allowing a faster return to resting heart rate
120
What is the effect of prolonged bed rest on insulin sensitivity?
Reduces insulin sensitivity, increasing the risk of metabolic diseases
121
What does EPO stand for?
Erythropoietin
122
What organ produces EPO?
Kidneys
123
What triggers increased EPO production?
Hypoxia (low oxygen)
124
What transcription factor regulates EPO expression?
HIF-1 (Hypoxia-inducible factor 1)
125
What does HIF-1 stand for?
Hypoxia-inducible factor 1
126
What is the role of HIF-1α in EPO signaling?
Activates transcription of the EPO gene under hypoxia
127
What happens to HIF-1α in normoxia?
It is hydroxylated and degraded
128
What happens to HIF-1α in hypoxia?
It avoids degradation and activates gene transcription
129
What post-translational modification regulates HIF-1α?
Hydroxylation
130
How does HIF-1 activate EPO gene transcription?
By binding to hypoxia response elements with HIF-1β
131
What is a hypoxia response element?
A DNA sequence that binds HIF-1 for gene activation
132
Which coactivator helps HIF-1 induce gene expression?
CBP (CREB-binding protein)
133
What other gene besides EPO is activated by HIF-1?
VEGF
134
What is the function of EPO?
Stimulates red blood cell production
135
What effect does EPO have on reticulocytes?
Prevents apoptosis and promotes maturation
136
What is a reticulocyte?
An immature red blood cell
137
Is EPO signaling limited to the bone marrow?
No, it also affects the brain and other tissues
138
What effect does EPO have in the brain?
Neuroprotective, possibly via BDNF regulation
139
What does BDNF stand for?
Brain-derived neurotrophic factor
140
How quickly does EPO increase after altitude exposure?
Rapidly within hours to days
141
What increases hematocrit at altitude?
EPO-induced red blood cell production
142
Does EPO directly sense oxygen?
No, HIF-1α senses oxygen and regulates EPO transcription
143
What is the main physiological trigger for HIF-1 activation?
Low partial pressure of oxygen (PO2)
144
How is HIF-1α degraded?
Via oxygen-dependent hydroxylation and proteasomal degradation
145
What does EPO prevent in precursor cells?
Apoptosis
146
What happens to transcriptional activity of HIF-1 under normoxia?
It is reduced due to degradation of HIF-1α
147
What enables HIF-1 to activate gene expression?
Stabilization of HIF-1α under hypoxia
148
What signaling effect does EPO have beyond erythropoiesis?
Neuroprotection and anti-apoptosis
149
Is HIF-1 activity in skeletal muscle during altitude well understood?
Not clearly established in humans
150
What general role does HIF-1 play in hypoxia?
Master regulator of cellular adaptation to low oxygen
