Exam 1 Flashcards
The director of the Harvard Fatigue Laboratory was
David Bruce Dill
The European scientist who was awarded a Nobel Piece Prize for his work measuring heat production during muscle contraction and recovery from exercise was
Archibald Vivian (A.V.) Hill
The Scandinavian scientist that won the Nobel Piece Prize for his work on the regulation of capillary blood flow to skeletal muscle was
August Krogh
The American researcher the performed early pioneering studies on progressive resistance training was
Thomas Delorme
The researcher that is considered to be the father of exercise biochemistry and from Wash U in St. Louis Missouri
John Holloszy
The outstanding Scandinavian that founded Copenhagen Muscle Research Center was
Bengt Saltin
The American researcher that was instrumental in promoting research in exercise molecular biology was
Frank Booth
The discovery that skeletal muscle is an endocrine organ and releases myokines was made by
Bente Pedersen
The University of Minnesota researcher that conducted semi-starvation studies and developed the K-ration for WWII
Dr. Ancel Keys
The Harvard University Professor that had guided research into the effects of exercise on browning of white fat cells which may increase resting energy expenditure is
Laurie Goodyear
What is a myokine
a signal from a muscle
What does ACSM stand for
American College of Sports Medicine
When was ACSM founded
1954
ACSM mission statement
ACSM advances and integrates scientific research to provide educational and practical applications of exercise science and sports medicine.
Equation for work
force x distance
Equation for power
work/time (rate at which work is being done)
Direct Calorimetry
Measurement of heat production as an indication of metabolic rate
Indirect calorimetry
Measurement of oxygen consumption as an estimate of resting metabolic rate
equation to calculate VO2 with the metabolic cart
VO2 = VE (FiO2-FeO2)
FiO2 constant
20.93
What does VE stand for
Ventilation
How are we able to estimate kcal expenditure from doing Open Circuit Spirometry?
By measuring the amount of O2 consumed
VO2 =
Volume of O2 inspired - volume of O2 expired
Percent of CO2 in air
.03%
Percent of FiO2 in air
20.93%
Percent of N in air
79%
What percent of what we breath out is FeO2?
19%
Components of the metabolic cart
- Computer
- Mixing chamber
- Gas analyzers
- Heated Pneumotach
- Two-way breathing valve
Hemodynamic equation for VO2
VO2 = Q x a-vO2 diff
What does Q stand for
Cardiac Output (stroke volume x Heart Rate)
What does avO2 diff mean
Arterial-venous oxygen difference
What does the dot above VO2 and Q stand for
Per minute
What does the line above the second small v stand for
Mixed venous return
Relative vs absolute VO2
Relative - relative to the person’s body weight in mL/kg/min
Absolute - in L/min
Why bother representing VO2 in relative terms?
It can give a more accurate representation of fitness level based on a person’s mass
What does MET stand for?
Metabolic equivalent
What is the resting value of 1 MET?
3.5 mL/kg/min
Running economy
- Oxygen cost of running at a specific speed
- Lower VO2 at same speed indicates better running economy
Two athletes run at 6mph, one consumed 35 mL/kg/min and the other 45 mL/kg/min. Which one is indicating greater running economy?
The one running at 35 Ml/kg/min because he has a lower VO2
Homeostasis
Tendency to resist change in order to maintain a stable, relatively constant internal environment
Who created the terms homeostasis and fight or flight?
Walter Cannon
Are steady state and homeostasis the same thing?
No, homeostasis means it can change and a steady state means that it does not change
What is hormesis
A process in which low-to-moderate doses of a potentially harmful stress results in a beneficial adaptive effect on the cell or organism
What is MAP
Mean Arterial Pressure
What is the first MAP equation
MAP = Q x TPR
What does TPR stand for?
Total peripheral resistance
What is the second MAP equation?
MAP - diastolic BP + 1/3 pulse pressure
What is pulse pressure
systolic - diastolic BP
What is negative feedback?
Response reverses the initial disturbance in homeostasis
What does the sensor or receptor of a biological control system do?
Detects change in variable
What does the control center of a biological control system do?
Assesses input and initiates response
What does the effector of a biological control system do?
Changes internal environment back to normal
Negative feedback example
Thermal receptors send message to temperature control center in brain. Response by skin blood vessels and sweat glads regulates temperature
What do cell signaling pathways do?
- Communication between cells using chemical messengers
- Coordinates cellular activities
- Important for maintaining homeostasis
Intracrine signaling
Hormone that acts inside the cell that it came from
Juxtacrine signaling
Cell signaling that occurs between two adjacent cells
Autocrine signaling
Cell releases a chemical messenger into its extracellular fluid that then acts upon the cell that is came from
Paracrine signaling
Signals produced by cells act locally on nearby cells to bring about cellular responses
Endocrine Signaling
Cells release chemical signals into the blood that are carried throughout the body
What so heat shock proteins do?
Repair damaged proteins in cells
Examples of what heat shock proteins have to defend against
temp alterations, oxidative stress, glucose/glycogen depletion, altered pH etc…
Steps of protein synthesis
- Exercise activates cell signaling pathways
- Activates transcriptional activator molecule
- Transcriptional activator binds to gene promoter region
- DNA transcribes to mRNA
- mRNA leaves nucleus and binds to ribosome
- mRNA translated into protein
This improves the cell’s ability to maintain homeostasis
What is metabolism?
The total of all cellular reactions and and chemical pathways that result in the synthesis or breakdown of molecules
What is bioenergetics?
The chemical processes involved with the production of cellular ATP
Where is the subsarcolemma mitochondria located?
Directly beneath the cell membrane
Where is the intermyofibrillar mitochondria located?
near the myofibril proteins
Endergonic reactions
Require energy to be added to the reactants (ex: glycolysis)
Exergonic reactions
Release energy (ex: exegetic burning of glucose in cellular respiration is used to make ATP; hydrolysis of ATP
Coupled reactions
Liberation of energy in an exergonic reaction drives and endergonic reaction
Hydrolysis of ATP formula
ATP + H2O -ATPase> ADP + Pi + H + energy
Synthesis of ATP equation/phosphagen system primary equation
CrP + ADP + H - Creatine Kinase > Cr + ATP + H20
Oxidation
Losing an electron (NADH > NAD+ or Pyruvate to acetyl CoA)
Reduction
Gaining an electron (NAD+ > NADH or pyruvate to lactate)
What does NAD stand for =?
Nicotinamide adenine dinucleotide
What does FAD stand for?
Flavin adenine dinucleotide
What is gluconeogenesis?
Synthesis of glucose from amino acids, lactate, glycerol, and other short carbon-chain molecules (ex: I can use lactate to produce glucose in the liver)
What is glycogenolysis?
The breakdown of glycogen into glucose (I can break down carbs (glycogen) into glucose)
Phosphagen system
- ATP/PC
- Lasts 6-10 seconds
- 100 meter dash/anaerobic sports
- PCr approximately 4 times better reserve than “stored” ATP
Phosphagen system secondary equation
ADP + ADP -adenylate kinase> ATP + AMP
PCr resynthesis
Fast component
- Independent of pH
- 20 seconds
- rate controlled by ADP levels
Slow component
- Dependent on pH
- 3-4 minutes
- Return of muscle cell to homeostatic intracellular pH
Fast glycolysis
- 2 (glucose) or 3 (glycogen) NET ATP
- Significant contribution to ATP generation during vigorous exercise
- End product is lactate
Fates of lactate
- Converted to pyruvate by mitochondria for intracellular fuel
- Cell to cell fuel (Type II to Type I)
- Cell to distant cell (goes to liver/brain/heart to be converted back k into glucose)
Hexokinase
Uses an ATP to phosphorylate glucose (1st step: glucose to glucose 6 phosphate)
Phosphorylase
Breaks down muscle glycogen into glucose 1 phosphate
Phosphofructokinase (PFK)
- Rate limiting enzyme
- Uses an ATP to convert fructose 6-phosphate to fructose 1,6-bisphosphate
Lactate dehydrogenase (LDH)
Enzyme used to convert pyruvate into lactate
Slow Glycolysis
- H+ binds to NAD+ and enters into the mitochondria
- NAD+ does not enter into the mitochondria but is reused to grab more H+
- if left unattached H+ can reduce pH and affect glycolysis
H+ mitochondrial shuttles
- Malate asparte shuttle (cardiac)
- glycerol phosphate shuttle
(skeletal muscle)
When is H+ released during glycolysis?
- ATP hydrolysis
- Glyceraldehyde-3-phosphate (last reaction before splitting)
- 1,3-Diphosphoglycerate reaction (1st reaction after glycolysis splits into two columns)
What happens to H+ in the mitochondria?
- Picked up by FAD+ which forms FADH2
- It is used in oxidative phosphorylation to form ATP
Why is the H+ binding to FADH2 and inefficient exchange?
FADH2 only generates 1.5 ATP in the electron transport chain (ETC) while NADH would have generated 2.5 ATP in the ETC
Lactate trasport method
Carrier protein called monocarboxylate transporters (MCT) are used to diffuse lactate across sarcolemma membrane
What is the primary way glucose gets into a cell during exercise?
GLUT4
Bicarb buffering
H+ + HCO3- (bicarb) -> H2CO3(carbonic acid) -> CO2 + H2O
What is the name of the VCO2 VO2 graph?
V-Slope method of anaerobic threshold determination
Why is CO2 a nonlinear increase in the V-Slope method of anaerobic threshold determination graph?
The person is working harder so the body is using oxygen to create energy and the CO2 is building in the body as lactic acid is accumulating
What happens to the pyruvate molecule in slow glycolysis?
It is transported into the mitochondria and oxidized by NAD+ forming acetyl CoA
What happens when pyruvate is converted into Acetyl CoA?
CO2 and NADH are formed
Main purpose of the Krebs cycle?
- ATP minimal (get 1 GTP which converts into 1 ATP)
- NADH
- FADH2
- CO2 produced
What is the common denominator for entry into the TCA?
Acetyl CoA
What is IDH?
Isocitrate dehydrogenase (rate limiting enzyme in the citric acid cycle)
What is CS
Citrate synthase (first enzyme used in the citrus acid cycle)
What do dehydrogenases do?
They catalyze the transfer of a hydrogen and an electron
Can the Krebs cycle speed up?
Yep, lots
First product formed in the TCA?
Citric acid from Acetyl CoA
Percent O2 in calibration tank in metabolic cart?
16%
Percent CO2 in calibration tank?
4%
What is the purpose of the heated pneumotach?
Flow sensing device to integrate an airflow into a volume measurement
What does ATPS stand for?
Ambient Temperature, Pressure, Saturated
What does STPD stand for?
Standard Temperature, Pressure, Dry
If I exercise at an intensity where I consume 1 liter of oxygen per minute, about how many kcal am I burning?
5 kcal per minute
Assumptions of sub maximal exercise testing
- There is a linear relationship between HR, oxygen uptake, and workload
- The maximum HR at a given age is uniform and that the predicted maximal HR equation is thus accurate (220-age) (about 10-12 bpm error with this)
- The mechanical efficiency (cygnet uptake at a given workload) is the same for everyone (likely on bike, could vary on treadmill)
What is OBLA?
Onset of blood lactate accumulation (where the amount of lactate starts to spike on a graph)
Why doesn’t lactate increase linearly as soon as exercise starts?
We aren’t reliant on fast glycolysis for our energy system at that point and there is a latency period where the lactate forms in the muscle and it takes time for it to end into the blood stream
What level of lactate accumulation might indicate the lactate threshold?
The point in the V indicated the lactate threshold
Treadmill walking equation
VO2 = speed x 0.1 + [(speed x %elevation)x1.8] + 3.5
Treadmill running equation
VO2 = speed x 0.2 + [(speed x %elevation)x0.9] + 3.5
What do the 0.1, 0.2 mean
Oxygen cost of horizontal work
What do the 1.8, 0.9 mean?
Oxygen cost of vertical work
What does the 3.5 represent?
Resting oxygen consumption/ 1 MET
Leg Cycle Ergometer Equation
VO2 = (10.8 x watts / mass) + 7
What does the 10.8 represent in the cycling equation?
IDK
What does the 7 represent in the cycling equation?
Cost of unloaded cycling is 3.5 and the resting oxygen consumption is 3.5 which added up equals 7
What is economy
The oxygen requirement for a specific speed/power output
- measured by oxygen uptake
- lower VO2 at same speed indicates better economy
What does PPAR-delta do?
Regulates important cellular metabolic functions that contribute to maintaining energy balance
What is MCT 1?
- Co-transporter of lactate and a proton
- Found primarily in aerobic muscle (type 1, cardiac muscle)
- increase as a result of endurance training contributing to lactate oxidation (using it to generate an ATP)
Production of lactate
Consumes protons from reactions in glycolysis and helps keep glycolysis going
MCT 1
Found in type I fibers
MCT 4
Found in type IIfibers and exports lactate and H+ out of the cell
