anaerobic energy provision Flashcards
atp reactions free energy
ATP + H2O –> ADP + Pi = -30.5 kj/mol
ADP + H2O –> AMP + Pi= -30.5
ATP+H2O–> AMP + PPi = -40.6
PPi + h2o –> 2Pi = -31.8
atp
atp has high energy phosphate bonds which provide energy for muscle contraction
provides chemical energy that can be converted into other forms of energy used by living cells
energy for muscle contraction- ATP hydrolysed by myofibrillar ATPase
ATPase on myosin hydroluses the ATP to access energy and myosin head moves away from the actin filament
ADP and Pi remain bound to myosin
bioenergetics
ATP storage in the cell is very limited (~2secs)
body must constantly synthesise new ATP- if not= rigor mortis
rigor mortis- ATP cannot unbind from myosin so muscles will stay in contracted state
ATP-PCr- anaerobic metabolism
glycoloytic system- anaerobic metabolism- blood lactate test
oxidative system- aerobic metabolism- vo2 max test
ATP-PCr system
atp yield= 1 mol atp per mol of substrate (pcr)
recycling atp during exercise untul used up (~3-15s max exercise)
pcr energy cannot be used to cellular work but can be used to reassemble atp- as atpase only accepts atp
creatine content vs exercise intensity
muscle atp reduces slightly as exercise intensity reaches highest level
muscle lactate increases as EI increases
muscle PC decreases as EI increases
creatine supplementation
PCr + ADP + H–> Cr +ATP
adp increases can be de;ayed as there will be more atp production
cross bridge cycling is slowly improved
osmotic activity of creating higher water cell content= weight gain
- potential reason why creatine is high in animal sprinters
myokinase reaction
ADP +ADP –> ATP + AMP
limited capacity to produce ATP
only important during high intensity exercise - activated when pH falls
AMP is activator of enzymes involved in glycogen breakdwon- can help us to access further energy stores
anaerobic glycolytic system
breakdown of glucose/glycogen via glycolysis
ATP yield- 2-3 mol ATP per mol of substrate (glucose or glyc respec.) or 1-1.5 mol atp per lactate molecule if all pyruvate is converted to lactate
duration- 12s to 2 min
key enzymes in glycolysis and krebs
phosphofructokinase- glycolysis
citrate synthase- krebs cycle
succinate dehyrogenase- krebs
all 3 enzymes are rate limiting
enzyme control
CK controls rate of ATP prod in ATP-Pcr system
negative feedback system- when atp levels fall (adp increases) CK activity increases
when ATP increases, CK activity decreases
PFK glycolytic system- rate limiting
low atp (high adp)= increase in PFK activity
high atp= PFK activity decreases
also regulated by products of krebs cycle
enzymes and training status
aerobically trained athletes will have much greater nezymes activities for the oxidative systems such as succinate dehyrogenase
anaeorbically trained will ahve hreater activity for anaerobic enzymes such as CK and myokinase
muscle fibre type and enzymes
phosphorylase
- type 1= 2.8
- type 2a= 2.8
- type 2x= 8.8
PFK
- type 1= 7.5
- type 2a= 13.7
- type 2x= 17.5
Succinate D
- 7.1
- 4.8
- 2.5
citrate synthase
- 10.8
- 8.6
- 6.5
oxidative metab
from glucose- energy will last approx 90 mins before new energy source is required
from fat= almost unlimted stores- approx 10,000 min
wingate testing
30s all out sprint on cycle ergometer
applying the correct load ~7.5% of body mass
determination of peak power, fatigue index
high fatigue index doesnt mean less fit, may mean individual reaches higher power outputs
fatigue index= (peak power - lowest power)/ peak power
x100
fibre type and ATP utilisation
in contrast to endurance exercise, there are reductions in muscular ATP content during all out sprints
in type 1 muscle, takes longer to drop than type 2a and 2x
2x takes longest time
