Question

In order to contract, muscle fibers need

a. carbon dioxide
c. energy
b. wastes
d. water

Answer 1

C. Energy

In order for anything to move, it will require energy

Answer 2

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.