Feb 7th Content Flashcards
What is the only compound the body can use for energy driven processes
ATP
What is the bioenergy currency in the cells of all tissues
ATP
Energy is stored between
2nd and 3rd phosphate groups
Three Energy Systems
ATP-PCr, Glycolytic, Oxidative Metabolism
ATP-PCr occurs in
the cytoplasm
Which energy system has the fastest rate of ATP
ATP-PCr
Which energy system has the shortest duration for producing ATP
ATP-PCr
ATP-PCr system forms ATP with
creatine phosphate without oxygen
Glycolytic occurs in
the cytoplasm
Which energy system has a moderate rate and duration of ATP production
Glycolytic
Glycolytic energy system breaks down
CHO
CHO broken down by the glycolytic system is stored
in the muscle or glucose delivered to the blood
Cho broken down by the glycolytic system s used to
resynthesize ATP
Oxidative Metabolism occurs in
the mitochondria
Which energy system has the slowest rate of ATP production
Oxidative Metabolism
Which energy system has the longest duration at which ATP can be produced
Oxidative Metabolism
Oxidative Metabolism includes
KC and ETC
Oxidative Metabolism forms ATO from
breakdown of fatty acids using oxygen in the mitochondria
Energy derived from reactions are used to drive
activity
Fat breakdown –>
ATP
ATP fuels
actomyosin cross-bridge cycling
Actomyosin cross-bridge cycling reaction catalyzed by
mATPase
Actomyosin cross-bridge cycling yields
energy + ADP + Pi
All three energy systems are
active at any given time
Contribution of energy systems is primarily dependent on
intensity of activity and duration of activity
ATP-PCr prevents energy depletion by
quickly reforming ATP from ADP + Pi
1 ATP is produced from
1 PCr
Enzyme to break apart PCr
creatine kinase (CK)
Creatine kinase is highest in which fibers
T2b > T2a > T1
The energy from the breakdown of PCr is used for
regenerating ATP
How much ATP does the body store at any given time
80-100 g
ATP is stored in
muscle on myosin head
ATP concentrations during experimentally induced muscle fatigue
only slightly decrease (50-60% of pre-exercise levels)
ATP-PCr through CP and creatine kinase reaction serves as
energy reserve for rapidly replenishing ATP
ADP + creatine phosphate <–
creatine kinase
creatine kinase –>
ATP + creatine
Oral bioavailability of ATP is…
not bioavailable, no reason to supplement
ATP is well maintained during what duration of sprinting
8-10 s
PCr is rapidly depleted during _________ to supply
sprinting; Pi and ADP
Adenylate Kinase (myokinase) Reaction
replenish ATP, important for AMP
AMP is a
powerful stimulant of glycolysis
AMP helps to breakdown more
CHO
2 ADP <–
adenylate kinase
adenylate kinase –>
ATP + AMP
How is the ATP-PCr controlled
law of mass action
ATP + H2O <–
ATPase
ATPase –>
ADP + Pi + H
Buildup of ADP will increase rate of
creatine kinase and adenylate kinase reactions
Contribution of phosphocreatine and aerobic metabolism to energy supply study purpose
examine relationship between metabolic status of muscle before a second sprint ad subsequent performance and changes in muscle metabolites during sprint
Contribution of phosphocreatine and aerobic metabolism to energy supply study methods
2 maximal cycle ergometer sprints, separated by 4 minutes recovery; main trial, 30 s followed by 30 s, 2nd main trial, 30 s followed by 10s
Contribution of phosphocreatine and aerobic metabolism to energy supply study results
power output less on second trial, energy supply increased during trial 2
Contribution of phosphocreatine and aerobic metabolism to energy supply study conclusion
completely replenish ATP by 8 minutes, but power output may not be the same
End result of glycolysis
lactate
Directions of lactate at the end of glycolysis
remain lactate (fast) or shuttled into mitochondria (slow)
Formation of lactate is catalyzed by
enzyme lactate dehydrogenase (LDH)
Lactate is highly correlated with
fatigue
Resting blood lactate
.5 to 2.2 mmol/L
Exercise blood lactate
25 to 30 mmol/L
Rate of production of lactate higher in which type of muscle fibers
T2
Lactate is used
intermediately, exchanged between different tissues, source of carbon for oxidation, and gluconeogenesis
Lactate used in
cori cycle, cell to cell La shuttle, intracellular La shuttle
La transported across mitochondria membrane by
MTC1
Mitochondria contrain
LDH
La is produced and consumed by
same muscle fiber
Cori cycle is shuttling of
lactate to liver to form glucose
Blood lactate concentrations reflect
lactate production and clearance
Normal blood lactate levels return within
1-hour post-exercise
Light activity post-exercise clears lactate more than
inactivity
Blood lactate accumulation is greatest following
high-intensity, intermittent exercise
Cell to Cell La Shuttle contraction takes lactate into
muscle to make ATP’ breaks down faster
Glycolysis leads to
krebs cycle
Pyruvate that eneters mitochondria is converted to
acetyl-CoA
One acetyl-CoA is formed it enters the
krebs cycle
NADH enters the
ETC to help resynthesize ATP
Where does malate-aspartate shuttle predominate
heart
here does glycerol-phosphate shuttle predominate
skeletal muscle
There is an inverse relationship between
given energy system max rate of ATP production and total amount of ATP capable to be produced over a long period of time
Which system has the highest rate of ATP production
phosphagen
Which system has the highest capacity of ATP production
oxidation of fats and proteins
Which system has the lowest rate of ATP production
oxidation of fats and proteins
Which system has the lowest capacity of ATP production
phosphagen
Which system is 0-6 s and has a extremely high intensity level
phosphagen
Which system is 6-30 s and has a very high intensity level
phosphagen and fast glycolysis
Which system is 30 s - 2 minutes and has a high intensity level
fast glycolysis
Which system is 2-3 minutes and has a moderate intensity level
fast glycolysis and oxidative
Which system is > 3 minutes and has a low intensity level
oxidative
The extent to which each of the energy systems contributes to ATP production depends on
primarily intensity of activity and secondarily on duration
Phosphocreatine can decrease markedly (50-70%) during
first stage of high intensity exercise and almost eliminated as result of exercise to exhaustion
Post-exercise phosphagen repletion can occur in
relatively short period
Complete resynthesis of ATP appears to occur within
3-5 minutes
Complete phosphocreatine resynthesis can occur within
8 minutes
Grams of glycogen stored in muscle
300-400 g
Grams of glycogen stored in liver
70-100 g
Rate of glycogen is related to
exercise intensity
At relative intensities above 60% of maximal oxygen uptake, muscle glycogen becomes
increasingly important energy substrate
Repletion of muscle glycogen during recovery is related to
post-exercise CHO ingestion
Repletion optimal if
.7 to 3 g of CHO per kg of body weight ingested every 2 hours following exercise
Effect of oral creatine supplementation on muscle PCr
did not result in PCr content
Effect of age, diet, and tissue type of PCr response to creatine
who you are effects your benefit; older adults and vegetarians»_space;»
Mixed muscle glycogen from what muscle fibers
T1 and T2
Increase in intensity has more
glycogen depletion
Exercise taken to failure will have
similar depletion levels
Muscle fiber activation study resuts
similar depletion seen due to failure; T1 and T2 fiber glycogen depletion determined by neither load or repetition during resistance exercise performed to failure
CHO supplementation study design
isokinetic bout, treatment, isokinetic bout
CHO supplementation study results
deplete less glycogen when training, drink a CHO bev; glycogen isn’t limiting factor to perform testing
Breakfast Omission Study
for exercise sessions to failure, advisable to recommend consumption of high carb meal before exercise is training in morning
Low muscle glycogen concentration study design
one-legged protocol
Low muscle glycogen concentration study results
muscle glycogen concentration higher in norm group
stimulate MPS even with low muscle glycogen available
ingestion of PROT/CHO drink enhances anabolic response
commencing training with low muscle glycogen does not impair anabolic response in early recovery period
195 minutes on average to exhaust glycogen on one leg
Least effective limiting factors in light exercise
ATP and creatine phosphate, lower pH
Most effective limiting factors in light exercise
muscle glycogen, liver glycogen
Least effective limiting factors in moderate exercise
ATP and creatine phosphate, fat stores
Most effective limiting factors in moderate exercise
muscle glycogen, lower pH
Least effective limiting factors in heavy exercise
liver glycogen, fast stores
Most effective limiting factors in heavy exercise
lower pH, followed by ATP and creatine phosphate and muscle glycogen
Least effective limiting factors in very intense exercise
muscle glycogen, liver glycogen, fat stores, lower pH
Most effective limiting factors in very intense exercise
ATP and creatine phosphate
Least effective limiting factors in very intense repeated exercise
liver glycogen, fat stores
Most effective limiting factors in very intense repeated exercise
ATP and creatine phosphate, muscle glycogen, lower pH
Limiting factors
ATP and creatine phosphate, muscle glycogen, liver glycogen, fat stores, lower pH
Exercise intensity (% max power output) 0-5s, 30 s, 60s, 90s
0-5 s = 100
30 s = 55
60 s = 35
90 s = 31
Contribution of anaerobic mechanisms (%) 0-5s, 30 s, 60s, 90s
0-5 s = 96
30 s = 75
60 s = 50
90 s = 35
Contribution of aerobic mechanisms (%) 0-5 s, 30s, 60s, 90s
0-5 s = 4
30 s = 25
60 s = 50
90 s = 65
The use of appropriate exercise intensities and rest intervals allows for the “selection” of
specific energy systems during training and results in more efficient and productive regimens
Interval training
emphasizes bioenergetic adaptations for more efficient energy transfer
Combination training
adds aerobic endurance training to training anaerobic athletes to enhance recovery
Combination training may reduce
anaerobic performance capabilities; gain in muscle girth, max strength, and speed/power related performance’ may be counterproductive to strength/power sports