Energy Systems 2 Flashcards
Explain role of ATP in providing energy for muscular contractions
ATP is the only energy that can be used for muscle contractions (duration 2-3 secs) and it is broken down into ADP, phosphate and energy in the presence of ATPase. Between 2nd and 3rd phosphate there is a high energy bond which is broken down to provide energy for contractions, however this only lasts 2-3secs
how does PC system works
PC system works by: When ATP levels fall, creatine kinase is stimulated. Creatine kinase breaks down Pc into a phosphate, energy and creatine (exothermic). The energy generated by this reaction, is then used to resynthesise ATP in ADP + P + energy (endothermic). This is a coupled reaction because the product (energy) in 1 reaction is used in the other reaction.
Adv of PC system
Adv of PC system are: No 02 delay Provides energy for power No fatiguing by products PC replenishes quickly 50% in 30 secs, 75 in 1min and 100 in 2-3mins
Dis adv of Pc system
Dis adv of APC system are:
Inefficient energy yield 1 : 1
Short duration 10secs max
Low PC stores
Site of reaction of aerobic system and controlling enzyme
Site of reaction of aerobic system is mitochondria and controlling enzyme is PFK
Adv of aerobic system
Adv of aerobic system are: High energy yield 1:38 Long duration No fatiguing by products Large glycogen and triglyceride store
Dis adv of aerobic system
Dis adv of aerobic system are: Only provides moderate intensity energy Delay for 02 delivery Reactions happen slowly For 1st 20mims glycogen is broken down, after 20mins, fat is predominant energy source.
What is energy continuum
Energy continuum is relative contribution is all energy systems to resynthesis of ATP, it depends on intensity and duration of activity.
How is lactic acid broken down
Lactic acid is converted into lactate ions and hydrogen ions, 5en bicarbonate combines with H ions, making carbonic acid which is unstable and breaks down into CO2 and H20.
Lactate can be converted into protein (urea) and sweated or urinated.
Can be converted into glucose and used as energy
Can be stored as glycogen.
What is sarcoplasm
Sarcoplasm is cytoplasm within muscle cells which holds stores of PC, glycogen and myoglobin
What happens when ATP levels fall and why do they fall
Drop in ATP levels is due to exercise because energy lasts for 2-3secs. When ATP levels fall, creatine kinase is stimulated.
Why can glycolytic system only be maintained for a few mins
Glycolytic system can only be sustained for a few mins because lactic acid causes fatigue and OBLA which increases acidity which denatures enzymes
What are characteristics of PC system
Characteristics of PC system are: Anaerobic Controlling enzyme Creatine kinase Site is sarcoplasm of muscle cell 1:1 energy yield
