Energy systems Flashcards
what does the body convert into energy
food (carbohydrates)
what are the three energy systems
- ATP - PC systems
- The short-term lactate anaerobic/ anaerobic glycolytic system
- the aerobic system
is the ATP - PC system aerobic or anaerobic
anaerobic
is the glycolytic system aerobic or anaerobic
anaerobic
is the aerobic system aerobic or anaerobic
aerobic
what is the energy source for the ATP - PC system
Phosphocreatine
what is the energy source for the glycolytic system
carbohydrate (glycogen - glucose)
what is the energy source for the aerobic system
carbohydrates and fats
what is the intensity and duration of the ATP - PC system
- single maximal movement
- 5-10s
what is the intensity and duration of the glycolytic system
- high to medium intensity
- 30s to 3 minutes (peaks at 45 seconds)
what is the intensity and duration of the aerobic system
- low
- 3 minutes + (duration depends on the fitness of the individual
how many molecules of ATP are resynthesized, for every molecule of PC
1
what happens when we run out of PC
we switch to another energy system
what is PC
Phosphocreatine
what does Pi + ADP produce
ATP
how quickly can ATP stores be replenished (ATP - PC system)
- take 3 minutes, to fully restore
- can restore 50% in 30 seconds
what are the advantages of the ATP - PC system ( state 4)
- ATP can be resynthesized rapidly using the ATP – PC system
- Phosphocreatine stores can be resynthesized quickly (30s - 50% replenishment and 3 mins – 100%)
- There are no fatiguing by-products
- It is possible to extend the time the ATP – PC system can be utilised through the use of creatine supplementation
what are the disadvantages of the ATP - PC system ( state 3)
- There is only a limited supply of phosphocreatine in the muscle cell, i.e. It can only last for 10 seconds
- Only one mole of ATP can be resynthesized for every mole of PC
- PC resynthesis can only take place in the presence of oxygen (when you reduce intensity of exercise)
what is the enzyme that breaks down phosphocreatine
Creatine kinase
example question, Name the main energy system being used in the 100m and explain how this system provides energy for the working muscles.
The main energy system that is being using during the 100m is the ATP – PC system. This system is an anaerobic system. When ATP is broken down into ADP, energy is released. We breakdown phosphocreatine with the use of the enzyme creatine kinase, in order to release a phosphate molecule, which binds with ADP in order to from ATP, so that the PC stores are replenished, (this process is using aerobic energy).
how many molecules of ATP are produced, when glucose is broken down
2 molecules
what is the enzyme that breaks down glucose and what does it break it down into
phosphofructokinase is the enzyme that breaks it down into pyruvic acid,
what is the enzyme that turns pyruvic acid into lactic acid, in the absence of oxygen
lactate dehydrogenase
what is the enzyme, that breaks down glycogen into glucose
glycogen phosphorylase
where does the process of glycolysis take place
in the sarcoplasm of the muscle cells
how many molecules of ATP does glycolysis produce
2 ATP molecules ( remember that 4 are actually produced, 2 of them are used for the process of glycolysis)
example questions Name the main energy system being used in the 400m and explain how this system provides energy for the working muscles (6 markers)
- The main energy system being used in the 400m would be the anaerobic glycolytic system.
- Takes place the sarcoplasm of the muscle cell.
- This system provides energy, by breaking down glycogen by glycogen phosphorylase.
- This forms glucose, glucose is then broken down by the process of glycolysis by the enzyme phosphofructokinase, in order to resynthesis 2 molecules of ATP and pyruvic acid.
- However, in the absence of oxygen, lactate dehydrogenase changes pyruvic acid into lactic acid.
how many molecules of ATP does the aerobic system produce, via that oxidation of 1 glucose molecule
38 ATP molecules
what are fats broken down into, before entering the Krebs cycle
they are broken down into acetyl coenzyme A
what happens in stage 1 of the Krebs cycle
- Glycolysis: this is anaerobic and takes place in the sarcoplasm of the muscle cell
- Glycolysis is the breakdown of glucose into to pyruvic acid (1 glucose molecules produces 2 ATP molecules)
- Before pyruvic acid enters the next stage (kerbs cycle) it is oxidised into 2 acetyl groups and is carried into the kerbs cycle by coenzyme A
what happens in stage 2 of the Krebs cycle
- The 2 acetyl groups diffuse into the matrix of the mitochondria and the kerbs cycle occurs (a complex cycle of reactions)
- The acetyl groups combined with oxaloacetic acid forming citric acid.
- Hydrogen is removed from the citric acid and C and H are given off (oxidative carboxylation)
- C forms C02, is transported to the lungs and breathed out
- H enters the electron transport chain.
- 2 ATP molecules are formed.
what happens in stage 3 of the Krebs cycle
- H is carried to the electron transport chain by H carrier (takes place in the cristae of the mitochondria)
- H splits into H ions and electrons are charged with potential energy
- H ions are oxidised to form H20, H electrons provide the energy to resynthesis ATP (34 ATP are formed)
what is Beta oxidation (do not need to know in super detail)
- Breaks down fats in the aerobic system.
- Stored fat is broken down into glycerol and three fatty acids for transportation in the blood.
- That fatty acids then undergo beta oxidation: and are converted into acetyl coenzyme A (the entry molecule for the Krebs cycle)
- From then on fat follows the same path as glycogen metabolism
- More ATP can be made from one molecule of fatty acids, than glucose which is why in long duration, low intensity exercise, fatty acids are the predominant energy source – but this does depend on the fitness levels of the performer.
what are the advantages of the aerobic energy system, state 3
- More ATP can be produced (36 - 38 ATP molecules)
- There an no fatiguing by products (co2 and h20)
- Lots of glycogen and triglyceride stores so exercise can last for a long time
what are the disadvantages of the aerobic system, state 2
- This is a complicated system so cannot be used straight away. It takes a while for enough O2 to become available to meet the demands of the activity and ensure glycogen and fatty acids are completely broken down.
- Fatty acid transportation to the muscles is low and also requires 15% more oxygen to be broken down compared to glycogen.
be able to describe the energy continuum graph
describe ATP generation in fast twitch ( type 2x) muscle fibres, state 3 reasons.
- The main pathway for ATP production, is via that lactate anaerobic system energy system.
- ATP production in the absence of oxygen is not efficient
- only two ATP produced per glucose molecule.
- Production of ATP this way if fast but cannot last for long as these fibres have least resistance to muscle fatigue
describe ATP generation in slow twitch (type 1) muscle fibres, state 3 reasons.
- The main pathway for ATP production is in the aerobic system.
- It produces the maximum amount of ATP available from each glucose molecule (up to 38 ATP molecules)
- Production of ATP is slow but these fibres are more endurance based so less likely to fatigue
what is oxygen consumption
the amount of oxygen, we use to produce ATP.
what is VO2 max
the maximum volume of oxygen that can be taken up by the muscles per minute (determined by weight).
what is sub maximal O2 deficit
when there is not enough oxygen, available at the start of exercise to provide all the energy (ATP) aerobically.
what is maximal oxygen deficit (MAOD)
an indication of anaerobic capacity
what are the factors that effect V02 max
- differences in age
- gender
- body composition
- lifestyle
- training V02
how do differences in age affect VO2 max
as we get older out VO2 max declines as our body systems become less efficient.
how does gender affect VO2 max
men generally have approx. 20% higher vo2 max than women
how does body composition affect VO2 max
a higher percentage of body fat decrease VO2 max
how does lifestyle affect VO2 max
smoking, sedentary lifestyle, poor diet, and poor fitness can all reduce VO2 max values.
how does training affect your VO2 max
V02 max can be improved by up to 10-20 percent following a period of aerobic training (continuous, fartlek and aerobic interval)
how does physiologically affect your VO2 max (state 5 out of a possible 10)
- Increased maximum cardiac output.
- Increased stroke volume/ejection fraction/cardiac hypertrophy.
- Greater heart rate range.
- Less oxygen being used for heart muscle so more available to muscles.
- Increased levels of haemoglobin and red blood cell count.
- Increased stores of glycogen and triglycerides.
- Increased capillarisation around the muscles.
- Increased number and size of mitochondria.
- Increased surface area of alveoli.
- Increased lactate tolerance.
what is OBLA
the onset of blood lactate
what is the energy continuum
the relative contribution of all three energy systems, to the resynthesis of ATP
what is lactate threshold
the point during exercise, at which lactic acid, quickly accumulates in the blood
what is the respiratory exchange ratio
the ratio, of carbon dioxide produced compared to oxygen consumed
what is lactate sampling
taking a blood sample, in order to see the proportion of your blood which contains lactate.
what is indirect calorimetry
the measurement of the amount of heat/energy, generated in a oxidation reaction, by determining the intake or consumption of oxygen or by measuring the amount of carbon dioxide, released and translating these quantities into a heat equivalent.
what is altitude training
usually done at 2500m + above sea level where the partial pressure of oxygen is lower
what is high intensity interval training
what is plyometrics
involves, repeated rapid stretching and contracting of muscles, to increase muscle power
what is SAQ (speed agility quickness)
- speed refers to how fast a person is able to move over a specified distance.
- good agility,m requires a combination of speed, coordination, balance and flexebility.
- trained thorugh dirlls, which include zig zag runs and foot laddres, in order to improve the multi directional movmetns, by developing ones neuromuscular system.
