energy systems Flashcards
name the three stages of the aerobic respiration
-glycolysis
-kreb cycle
- electron transport chain
what does ATP stand for
adenosine triphosphate
what is the structure of ATP
adenosine and 3 phosphates
What enzyme breaks down ATP
ATPase
give the formula for breakdown of ATP
ATP-> ADP + pi (inorganic phsophate) + energy
How is ATP resynthesised
3 energy systems
Name the three energy systems
- aerobic system
- ATP - PC system
- anaerobic glycotic system
How is respiration fueled (2 types)
food - carbohydrates
chemical - phosphocreatine
when is the aerobic system used ?
for low intensity high duration
high oxygen supply
which energy system is the most efficient
aerobic
what is the fuel source for aerobic respiration
carbohydrates - glycogen
high oxygen low intensity - fat
give the formula of gylcolysis
glycogen -> energy (2ATP) + pyruvic acid
where does glycolysis take place
sarcoplasm - fluid that surrounds nucleus of muscle
give the formula of the krebs cycle
pyruvic acid (no presence of o2) -> acetyl coA
acetyl coA -> energy (2ATP) + hydrogen ion (H+) + CO2
where does the krebs cycle tale place ?
matrix - inside the mitochondria
give the formula for the electron transport chain
hydrogen + O2 -> 34 ATP + water
whats the total energy yield for aerobic respiration
36 ATP
What is beta oxidation?
When fat is used as a fuel rather than carbs to fuel aerobic respiration
fatty acids undergo beta oxidisation whereby theyre converted into acetyl coA so it can be fed into the krebs cycle.
BUT requires 15% more 02
give 3 adv of the aerobic system
- 36 ATP produced
- no fatiguing byproducts
- lots of glycogen and triglyceride stores so excercise can last for a long time
give disadvantage of the aerobic system
- cannot be used straight away
enough o2 must become available to meet demands of activity and ensure fuel can be broken down
What is the fuel source of the ATP-PC system
phophocreatine
give the formula for the ATP -PC system
Phosphocreatine -> creatine +phosphate +1ATP
give advantages of the ATP -PC system
1.rapid availability
2.phosphocreatine stores can be resynthesised quickly (50% after 30s)
3. no fatiguing byproducts
give disadvantages of ATP-PC system
- limited supply of phosphocreatine in the cell (8-10s)
- least efficient system (1 mole of ATP)
give the formula for the anaerobic glycolytic system
glycogen -> 2ATP + pyruvic acid
How is energy released
the break down of atp .
breakdown of the triphosphate bond
How long does the anaerobic glycotic system last for
45s - 3min
give an advantage of the anaerobic glycotic system
ATP can be resynthesised quite quickly
In presence of o2 lactic acid converted back into glycogen via reverse glycolysis
Can be used for a sprint finish at the end of a 10000
Give a disadvantage of the anaerobic glycolytic system
- only 2 atp produced
- accumulation of lactic acid (fatiguing byproduct)
What is the energy contiuum
the contribution of different energy systems make to the production of energy depending on the intensity and duration of exercise
what muscle fibres are used for aerobic respiration
slow twitch muscle fibres for low to medium intensity
- endurance based fibres less likely to fatigue
Which muscle fibres are used for anaerobic respiration?
fast twitch (2a/b)
- inefficient, produces only 2atp and lactate production
What is oxygen consumption?
amount of o2 we use to produce ATP referred to as VO2
How much o2 does the average person consume a minute at rest
0.3-0.4 litres/ min
what happens to o2 consumption at the start of exercise?
INCREASES
we use more o2 to produce ATP so
consumption increases
What energy source is used for low intensity exercise
fats - requires 15% more o2
What is VO2 max ?
maximum volume of o2 that can be taken up and used by muscles per minute
What is sub maximal oxygen deficit ?
when there is not enough oxygen available at the start of exercise to provide all the energy aerobically
what happens to oxygen deficit as a person enters maximal exercise
oxygen deficit becomes bigger, have to work anaerobically fro longer
what is EPOC
excess post exercise consumption
amount of oxygen taken up during recovery above that that would have been consumed at rest
what are the two components of EPOC
fast
slow
what happens during the fast component of EPOC?
extra oxygen used to resarurate myoglobin, and restore ATP and phosopho creatine
What happens during the slow component of EPOC
- Removal of lactic acid
- maintenance of breathing and HR
- glycogen replenishment
- increase in body temperature
What is lactate threshold
point during exercise at which lactic acid rapidly accumulates in the blood (increase by 2 millimoles per litre of blood above resting levels.)
What is OBLA ?
point at which lactate levels go above 4millimoles per litre
How much lactate is in the average body at resting levels ?
1-2 millimoles per litre
What is buffering ?
Process which aids the removal of lactate but maintains levels of acidity in blood.
does this by acting like a sponge meaning athlete can work at higher intensity for longer without fatiguing
What are the factors affecting rate of lactate accumulation?
- intensity
- muscle fibre type
- rate of blood lactate removal
- respiratory exchange ratio
- fitness of performer
what is vo2 max ?
The maximum volume of O2 that can be taken up and used by he muscles per minute
7 factors affecting VO2 max
- lifestyle
- Body composition
- gender
- age
- genetics
- training
- physiological
do men or women have a higher vo2 max ?
men by 20 %
what physiological adaptations affect vo2 max ?
- myoglobin content
- stroke volume / cardiac output
- capillary density
- ## lactate tolerance
what are the 5 methods of measuring energy expenditure
- indirect calorimetry
- lactate sampling
- vo2 max
-direct gas analysis - respiratory exchange ratio
how does indirect calorimetry give an estimate of expenditure
how much CO2 produced vs how much O2 consumed at both rest and during aerobic exercise
What is RER
respiratory exchange ratio -
CO2 expired per minute ÷ O2 consumed per minute
