KINE 4010 Lecture 2: KINE 4010 - Sept. 14
15 Dec 2016
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KINE 4010 – Sept. 14th
Lecture 02: Anatomy of ATP – ATP-PC System (p. 7)
- Energy Metabolism During Exercise
o Cycle of ATP:
▪ 1) Goes from ATP (has 3 phosphates) – to ADP (has 2 phosphates)
• Breaks a high energy bond which releases 7kcal of energy AND an inorganic
phosphate
▪ 2) Goes from ADP and Pi – to ATP
• Breaks down glycogen, sugar and fats – to reassemble ATP
▪ Therefore – this cycle consists of going from ATP to ADP to ATP (repeated)
o ATPase: type of enzyme that breaks down ATP to provide useful cellular energy
▪ Types of ATPases:
• Myosin ATPase: specific ATPase housed in the myosin molecule (OR the myosin
cross-bridge)
o Break down ATP to ADP and inorganic phosphate – which releases
7kcal of energy – which is used in cross-bridge cycling
▪ Cross Bridge Cycling: myosin binding to actin and shifting so
that the sarcomeres can shorten and generate force – which
causes the muscles to contract (muscle contraction)
• Na-K ATPase: it breaks down ATP into ADP and inorganic phosphate – which
releases 7kcal of energy to pump sodium (Na+) and potassium (K+) in opposite
directions in the membrane
o Most famous ATPase (in the world)
o Involved in membrane potential
• Ca ATPase: it breaks down ATP – and uses that energy to pump calcium (Ca+2)
against its concentration gradient (uphill pumping) into the sarcoplasmic
reticulum
o Energy is required to pump against the concentration gradient – b/c its
pumping against a force – and that energy comes from breaking down
ATP
▪ Other Enzymes:
• Hexokinase
• Phosphokinase (more specifically Creatine Phosphokinase)
▪ NOTE: The -ase edig sigifies a ezye – which is a type of protein that catalyzes
reactions or take substrates to products faster
o However – if we just only broke down ATP – we would quickly run out of it
▪ In our cells – we only have enough ATP for a FEW contractions
▪ Must regenerate ATP right away – through metabolism
• Metabolism: regenerate and maintain constant amounts of ATP
o Break down big molecules (i.e. glucose, fatty acids, lactate) through
catabolism to regenerate ATP from ADP and phosphate
o 3 Systems of Energy Metabolism (Regeneration of ATP):
▪ 1) ATP-PC (or ATP-PCr or ATP phosphocreatine system)
• Simplest and fastest – has ONLY 1 reaction
• Easy to regulate and turned on quickly
▪ 2) Anaerobic Glycolysis (ONLY glycolysis)
• More complex and slower/sluggish – has 13 reactions
find more resources at oneclass.com
find more resources at oneclass.com
• Slower to turn on – supplies ATP (energy) in time
• Harder to get moving and generate ATP
▪ 3) Aerobic (Glycolysis, Pyruvate Dehydrogenase, Krebs Cycle and ETC)
• Most complex and slowest – has the MOST reactions
• Use multiple types of organelles
• More complex than just glycolysis
o B/c it involves the breakdown of fats and glucose (through glycolysis
and pyruvate dehydrogenase) to make ATP through the ETC (electron
transport chain)
▪ Therefore – it involves both cytosolic and mitochondrion
reactions
▪ These are the 3 systems we use when we exercise to immediately regenerate ATP from
ADP and Pi
▪ All three differ in their complexity (one is very fast, one is intermediate and one can last
for a very long time)
▪ These three different systems are TIME DEPENDANT (one is fast, one is sluggish and one
is very slow)
- What Happens During the First Seconds of Exercise?
o When you start exercising – you need the energy right away (ATP demand)
o Two Conditions:
▪ 1) Low Energy Demand (from Low Intensity Exercise)
• From standing still to a mild exercise – there was an increase in energy or ATP
demand (at the start of the rectangle)
o Therefore – needed ATP to do the exercise
• ATP demand increased at the start of exercise and REMAINED CONSTANT until
the end of exercise (ATP back down to basal level)
▪ 2) High Energy Demand (from High Intensity Exercise)
• From standing still to an intense exercise – the ATP demand (at the start of the
rectangle) was higher or more – compared to the mild exercise
o Therefore – needed even more ATP to do the exercise
• ATP demand increased at the start of exercise and REMAINED CONSTANT until
the end of exercise (ATP back down to basal level)
▪ Therefore – there are different amounts of ATP demand (need different amounts of
energy or ATP) to do different intensities of exercise
▪ Metabolism (the 3 systems of energy production) has to fill the square and provide an
ATP supply which meets the ATP demand
• Therefore – have an ATP demand (set by the intensity of the exercise) – and
must supply it from metabolism (the 3 systems of energy production)
▪ Initially – the ATP-PC system covers the initial onset of energy demand (inside the green
box) – the rest of the energy demand (rest of the black square) is supplied by the other
two systems (anaerobic glycolysis and aerobic)
• Why do’t the other two systes work right away?
o B/c they are multi-enzyme pathways that take longer to get going, to
upregulate or to activate (whereas ATP-PC is only one reaction)
find more resources at oneclass.com
find more resources at oneclass.com
Document Summary
Lecture 02: anatomy of atp atp-pc system (p. 7) Therefore this cycle consists of going from atp to adp to atp (repeated: atpase: type of enzyme that breaks down atp to provide useful cellular energy. Types of atpases: myosin atpase: specific atpase housed in the myosin molecule (or the myosin cross-bridge, break down atp to adp and inorganic phosphate which releases. 7kcal of energy which is used in cross-bridge cycling. Simplest and fastest has only 1 reaction. Easy to regulate and turned on quickly: anaerobic glycolysis (only glycolysis, more complex and slower/sluggish has 13 reactions. Therefore it involves both cytosolic and mitochondrion reactions. These are the 3 systems we use when we exercise to immediately regenerate atp from. Adp and pi: all three differ in their complexity (one is very fast, one is intermediate and one can last for a very long time)
