Question

Immediate source of ATP. PC + ADP -> (creatine kinase) ATP + C

a) Creatine phosphate (CP) is the immediate source of ATP.
b) Glycolysis is the immediate source of ATP.
c) Oxidative phosphorylation is the immediate source of ATP.
d) Gluconeogenesis is the immediate source of ATP.

Answer 1

Creatine phosphate (CP) is the immediate source of ATP for muscle contraction.

Step-by-step explanation:

The immediate source of ATP for muscle contraction is creatine phosphate (CP). In a resting muscle, excess ATP transfers its energy to creatine, producing ADP and creatine phosphate. When the muscle starts to contract and needs energy, creatine phosphate transfers its phosphate back to ADP to form ATP and creatine. This reaction is catalyzed by the enzyme creatine kinase and occurs very quickly; thus, creatine phosphate-derived ATP powers the first few seconds of muscle contraction.

However, creatine phosphate can only provide approximately 15 seconds worth of energy, at which point another energy source has to be used.

Therefore, option a) Creatine phosphate (CP) is the immediate source of ATP is the correct answer.