Muscle energetics Flashcards
What is the % of energy actually used for moving?
25% moving
75% heat
What happens when you have a high ATP:ADP ratio?
Signals are sent to the body to produce more ATP
What does the energy continuum contain? (3)
PCr (Phosphocreatine)
Glycolytic
Aerobic
What is the order of entry continuum over time? (3)
- At start PCr is immediate and others are slow to start
- Glycolytic then peaks as PCr declines, aerobic slowly inclines
- PCr decreases, Glycolytic decreases and aerobic increases
What does PCr produce and what is its drawback? (2)
Produces inorganic phosphate - allosteric inactivator
Poisonous and can cause tumours, cell death etc
What happens at high intensity exercise? (3)
- All fibres recruited
- 1-2 minutes
- Mostly PCr and Glycolytic
How is PCr replenished? (equation)
ADP + PCr ATP + Cr
What is the relationship between PCr and glycolysis?
PCr acts as a buffer for the lag of glycolysis
What happens as muscle glycogen decreases?
Muscle lactate increases
How long can we maintain intense exercise for with muscle glycogen?
90 minutes
What is a high blood lactate level?
12-25mmol/KG
How long can we rely on PCr and how long does it take to recover?
PCr: 1-2 minutes
2-3 minute rest to do further activity - HIE trainers must have large rests
What happens initially when HIE occurs in terms of O2 value?
Initially, an oxygen deficit occurs
Lag between O2 demand and supply
How does the body work with an oxygen deficit and what is the drawback of it?
ADP + ADP —> ATP + AMP
AMP is produced
Drawback: ammonia levels in blood stream increase
How is exercise hormonally regulated? (2)
ADP release - slightly less energy is being used
AMP release - energy being used fast and need more energy
What is phopshofructosekinase? (PFK)
Rate limiting enzyme in glycolysis (ATP –> ADP)
What is an example of positive feedback in glycolysis?
AMP and ADP - need to increase
What is an example of negative feedback in glycolysis?
ATP and PCr - regulate energy production
What is the aerobic:anaerobic ratio in a marathon?
95:5 (hills/gradients and at the end)
What are the energy sources used at different running distances? (3)
100m: PCr
200m - 800m: anaerobic glycolysis
800m - marathon: aerobic metabolism
What are the fuels used at the initial stages of exercise? (3)
Fat:carbs are equal
Fat derived from free fatty acids and triglycerides
Glycogen provides carbs
What fuels are used as exercise continues over a period? (2)
Decline in muscle glycogen stores - blood glucose becomes important
Plasma FFAs become more important
Over 240 minutes, what is the trend shown by phosphate dehydrogenase kinase and pyruvate dehydrogenase kinase?
Phosphate dehydrogenase kinase: Gradual increase
Pyruvate dehydrogenase kinase: Gradual increase to 120 then decline
What is muscle glycogen proportional to?
Performance
