How calcium ions participate in the muscle contraction

How calcium ions participate in the muscle contraction? Why do both muscle contraction and muscle relaxation use energy?

E

Expert

Verified

In muscle cells calcium ions are stored in sarcoplasmicreticulum. When a motor neuron emits stimulus for muscle contraction neurotransmitters called acetylcholine are liberated in the neuromuscular junction and sarcolemma is excited. The excitation is conduced to sarcoplasmic reticulum that then releases calcium ions in sarcomeres.

In sarcomeres calcium ions bind to troponin molecules associated to actin activating myosin binding sites of the actin. The myosin, then capable to bind to actin, pulls this protein and sarcomere shortens. The summation of simultaneous contraction of the sarcomeres and myofibrils constitutes muscle contraction. Throughout muscle relaxation the calcium ions return back to sarcoplasmic reticulum.

For myosin to bind to actin, and therefore for the contraction to take place, hydrolysis of one ATP molecule is essential. Throughout relaxation the return of calcium ions to the sarcoplasmic reticulum is an active procedure that spends ATP too. So both muscle relaxation and contraction are energy-spending procedures.

   Related Questions in Biology

  • Q : What is Phenyl ketonuria Phenyl

    Phenyl ketonuria is autosomal recessive metabolic genetic disorder characterised by the mutation in the gene of hepatic enzyme phenylalanine hydroxylase,which is an important enzyme to metabolize phenylalanine and tyrosine.Mutation in this gene causes

  • Q : Explain the secondary structure of a

    Explain the secondary structure of a protein?

  • Q : Harassment - Barriers to Diversity -

    Consciously shinning or verbally or physically abusing an individual because of membership of a particular group.

  • Q : Nucleophilic addition reaction Define

    Define the term nucleophilic addition reaction?

  • Q : Climax stage of ecological succession

    Write down the climax stage of ecological succession?

  • Q : In photosynthesis what is path followed

    In photosynthesis what is the path followed by the energy which are absorbed by plants?

  • Q : Effect of price supports or acreage

    Assume the government wants to raise farmers' incomes. Why do price supports or acreage restriction programs cost society more than simply giving farmer's money?Price supports & acreage limitations cost society more than the dollar cost of

  • Q : Deficiency of dietary iodine Which

    Which disease is caused by the deficiency of the dietary iodine?

  • Q : What is Capacity Planning Capacity

    Capacity Planning: It is any strategy which is used to recognize the amount of production needed to satisfy the demand for the services and goods produced by a business. The thought is to balance the purchase of resources, the maintenance of productio

  • Q : Future prospect of Organizational

    Based on the trend analysis, the filliping future prospects of Organizational Behavior can be inferred: 1. Organizational Behavior has reached the status of identifiable fields of study and applications respectively, with explicit implications goes human resource management in complex org

©TutorsGlobe All rights reserved 2022-2023.