ATP metabolism

Question 1

ATP structure

Answer 1

Question 2

characteristics of ATP

Answer 2

• ATP is a high energy nucleotide
• Negative charge on terminal oxygen of phosphate group acts like compressed spring
• Phosphoanhydride bonds = high energy bonds
• (ΔG = -6.3Kcal/mol) per P lost

Question 3

anabolic reaction (in terms of Gibbs Free Energy & ATP)

Answer 3

• +ΔG endergonic
• hydrolysis of ATP

Question 4

catabolic reaction (in terms of Gibbs Free Energy & ATP)

Answer 4

• -ΔG exergonic
• release of energy

Question 5

demand for ATP hydrolysis can be as high as…

Answer 5

1kg of ATP per minute

Question 6

utilisation of ATP during exercise

Answer 6

• electrical energy (nerve impulses)
• mechanical energy (muscle contraction)
• maintenance of body temperature (heat)

Question 7

changes in muscle ATP with rest & maximal exercise (ATP volume & maximal ATP hydrolysis)

Answer 7

Question 8

myokinase regulation

Answer 8

a form of ATP replenishment

Question 9

myokinase (function)

Answer 9

• enzyme that adds a phosphate group to ADP to make ATP
• anaerobic reaction
• maintains ATP during hard exercise

Question 10

Phosphocreatine (PCr)

Answer 10

highest phosphoryl transfer potential

Question 11

creatine kinase (function)

Answer 11

• rapidly drives ATP synthesis during hard exercise
• PCr : Cr (2:1) = greater ATP synthesis

Question 12

changes in muscle PCr with rest & maximal exercise (PCr volume & maximal ATP hydrolysis)

Answer 12

Question 13

Resynthesis of PCr stores…

Answer 13

… is slower than ATP

Question 14

comparing ATP regeneration before & after exercise (PCr, Cr, ATP, ADP & Pi)

Answer 14

Question 15

comparing energy generating pathways (phosphagen, glycolytic & mitochondrial respiration)

Answer 15