Adenosine Tri Phosphate (ATP): The universal energy currency

Question 1

Adenosine Tri Phosphate (ATP): The universal energy currency

Answer 1

• immediate energy source for muscle contraction
• last approximately 2-3 seconds
• ATPase is required to break the end chemical bond and ‘release’ the energy for muscle contraction
• Once ‘broken’, ATP can be re-synthesised

Question 2

why does it play. important role in physical activity

Answer 2

• It’s a high energy compound which releases energy to contract muscles
  -It’s the body’s only useable source of energy
  -It can be re-synthesised and re-used

Question 3

ATP-PC SYSTEM

Answer 3

• activities under 10 seconds
  -anaerobic system
• This system breaks down the fuel Phosphocreatine (PC)
• (CK) is triggered by the rise in ADP levels and facilitates this reaction. The high energy bond between phosphate and & creatine is broken and energy is released to re-synthesise ATP.
• PC lasts 8-10 seconds
• 1 pc : 1 atp
• fully recovered in 3 minutes but does require oxygen for this to happen.

Question 4

glycolytic system

Answer 4

10s - 3 minutes predominant
- fastest system for resynthesis
- carbs are stored in blood stream ad glucose and muscle as glycogen.
-Phosphofructokinase (PFK) is triggered by the fall in PC stores and the rise in ADP levels and facilitates the breakdown of glucose
- if glucose levels fall GP is released to break down glycogen = resynthesis
- 1 g : 2 atp
-

Question 5

anaerobic glycolysis

Answer 5

This reaction forms pyruvic acid which cannot be metabolised without oxygen and so a 3rd enzyme called lactate dehydrogenase (LDH) converts pyruvic acid to lactic acid. If exercise intensity remains high, lactic acid is allowed to accumulate muscle acidity rises (low pH), enzyme function is inhibited and ATP re-synthesis will slow

Question 6

stage 1 aerobic glycolysis

Answer 6

Glucose is still broken down by the enzyme PFK into pyruvic acid producing energy for continued ATP re-synthesis,
- 1: 2 atp
- because oxygen is available, lactic acid does not accumulate and we can continue to fully breakdown glucose by converting pyruvic acid into acetyl co-enzyme A (Acetyl Co-A).

Question 7

stage 2 krebs cycle

Answer 7

This stage occurs in the mitochondria. Acetyl Co-A combines with oxaloacetic acid to form citric acid. Citric acid is then oxidised which results in the production of carbon dioxide, the removal of hydrogen and enough energy to re-synthesise 2 more moles of ATP. We can easily remove carbon dioxide through breathing and the hydrogen moves onto stage 3

Question 8

stage 3 electron transport

Answer 8

The hydrogen atoms produced from the krebs cycle move into this stage of the aerobic process which occurs in the cristae of the mitochondria. Hydrogen atoms are carried by hydrogen carriers (NAD and FAD) and they split into hydrogen ions and electrons. Hydrogen ions combine with oxygen (oxidised) and form H2O,
- releases energy, enough to re-synthesise 34 moles of ATP.

Question 9

Excess Post-exercise Oxygen Consumption (EPOC):

Answer 9

“The volume of oxygen consumed post-exercise/during recovery above that at rest, to help return the body to its pre-exercise state”

Question 10

lactacid phase

Answer 10

• This phase is slow
• Full recovery normally seen within 1 hr - 24
• Uses up to 8 litres of oxygen to support a number of processes
• pyruvic acid can re-enter the Krebs cycle to make new energy (approx.50-70%)
• pyruvic acid can convert back to glucose in the bloodstream
• PA converted into protein in the liver , removed in sweat, urine or through expiration of carbon dioxide.
• Maintenance of ventilation, circulation & body temperature

Question 10

alactacid phase

Answer 10

• This phase is fast
• Fully complete in 3 minutes
• Uses up to 4 litres of oxygen to complete 2 processes:
• Re-synthesise ATP and PC stores
• 50% can be re-synthesised in 30 seconds
• Haemoglobin (Blood oxygen) & myoglobin (muscle oxygen) stores are replenished