Question

• Consider the processes involved in muscle contraction. Summarize in a few sentences the relationship between ATP and muscle contraction.

Answer 1

Answer-

According to the given question-

Relationship between muscle contraction and ATP Utilization can occur in following way-

• When an action potential pass down the axon of motor neuron on neuromuscular junction.and causes Acetylcholine release into synaptic cleft which attaches to Acetylcholine receptors present on motor end plate and generates action potential in cell membrane of muscle
• Action potential pass through T-tubules which causes opening of voltage gated Ca+2 channel in sarcoplasmic reticulum and release of Ca+2
• Ca+2 bind with troponin and pulls away tropomyosin from actin molecules for binding of myosin head
• Myosin by its heads make a cross-bridges with actin molecules and pull the actin towards center.
• ATP attaches to head of myosin and this leads to break of cross-bridge between actin and myosin after that hydrolysis of ATP the heads of myosin change the position to their original conformation, to next actin binding site and this causes sliding of actin along myosin and decreases the length of sarcomere, leads to muscle contraction.
• Relaxation of muscle occur when stimulus from the nerve stopped. After that Ca+2 which is present in sarcoplasm is removed and pumped back in sarcoplasmic reticulum,and Tropomyosin again bind switch troponin and blocks the actin site. relaxation can also be achieved when there is no ATP is available.