2.Exercise Psy lecture 2

winniesmith2's version from 2018-02-12 13:50

Section 1

Question Answer
structure of ATP Adenine and ribose make adenosine. Plus 3 inorganic phosphates
What is ATP energy for cells • ATP is the only form of chemical energy that can be converted into other forms of energy used by living cells • Energy for muscle contraction: Myofibrillar ATPase
ATP is storage in cell is limited sothe body must constantly snthesise new ATP (-2s worth of maximum contractions) (if not resynthesises -> rigor mortis).
3 main ATP synthesis pathways– ATP-PCr system (anaerobic metabolism) – Glycolytic system (anaerobic metabolism) – Oxidative system (aerobic metabolism)
What is the ATP-PCr system • ATP yield: 1 molATP per mol of substrate (PCr) • Recycling ATP during exercise until used up (~3-15 s maximal exercise) • PCr energy cannot be used for cellular work • PCr energy canbe used to reassemble ATP
Creatine content vs exercise intensity as you increase VO2 max (intensity) the more dependent you become on PCr to supply ATP.
Creatine (Cr) supplementation can be usedincreases the amount of ATP that can be made but negatively increases osmotic activity; higher water content -> weight gain (potentially why creatine is not excessively high in animal sprinters).
What is the reaction to form ATP from creatine PCr + ADP + H+ -> Cr + ATP
What is the myokinase reaction ADP+ ADP -> ATP + AMP (at the cost of 31 kJ/mol ADP)
When is the myokinase reaction used limited capacity to prduce ATP. Only important during high intensity exercise (activated when pH falls). AMP is activator of enzymes involved in glycogen breakdown.

Section 2

Question Answer
The anaerobic glycolytic system• Breakdown of glucose/glycogen via glycolysis • ATP yield: 2 to 3 molATP per mol of substrate (glucose or glycogen, respectively) • Duration: 15 s to 2 min
What are the key enzymes in glycolysis and the krebs cycle Phosphofructokinase (PFK) (rate limiting). Citrate synthase. Succinate dehydrogenase.
What does creatine kinase control rate of ATP production in ATP-PCr system. – Negative feedback system: • When ATP levels decrease (ADP increase), CK activity increase. When ATP levels increase, CK activity decreases
What does phosphofructokinase control (PFK); glycolytic systemRate limiting enzyme. Decrease in ATP (increase in ADP) -> PFK activity increases. Increase in ATP -> PFK activity decreases. Also regulated by products of krebs cycle.
Enzymes training and statusthose that are anaerobically trained habe more anaerobic enzymes and vise versa
Muscle fibre types and enzyme acitivity different types of muscle fibres are associated with different enzymes.

Section 3

Question Answer
PCr breakdown15s - 100m
Anaerobic glycolysis15-120s - 100-180m
oxidative metabolism (glucose)-90 min, half marathon
oxidative metabolism (fat)-10,000 min, 170 hours at 8km/h

Section 4

Question Answer
How do you calculate fatigue index (%)((Peak power- lowest power) / peak power) x100
in contrast to endurance exercisemuscular ATP reduces during all-out sprints.
What are the energy sources during wingate testingfirst ATP-phosphocreatine, then glycolytic, then aerobic
Name two reasons for the predominance of PCr-ATP metabolism and glycolysis early on in the Wingate test'fast'energy = can produce it quickly. Metabolic inertia.
Calculation of anaerobic energy contribution ('ATP turnover')2(change in ATP) - 1 change in PCR + 1.5 change in lactate + 1.5 change in pyruvate.
Reason one for calculation of anaerobic anergy 1 ATP can provide energy to build 2 ATPs from 2 ADPs (as 2 active phosphates can be cleaved per ATP). If you find 1 less ATP after an intervention, it indicates that 2 ATPs could have been created using the energy of its metabolisation. factor 2
Reason two for calculation of anaerobic energy contribution – 1 less PCr indicates that 1 ATP has been produced. factor 1
Reason three for calculation of anaerobic energy contribution 2 more lactate or 2 more pyruvate molecules indicate that 3 ATPs have been produced . factor 1.5