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?
Expert
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.
Is neural impulse generated by stimulus which triggers arch reflex restricted in the neurons of this circuit?
State the normal sign of electric charge between two sides of the neuron plasma membrane? State the potential difference (voltage) which is produced between these two sides? What is that voltage known as?
Demonstrate mass transportation across the cell membrane.
What is the difference between an acid and a base?
SAP is the name of the corporation founded in the year 1972 under the German name “Systems, Applications, and Products in Data Processing” is the leading ERP (that is, Enterprise Resource Planning) software package.
Various conclusions may be drawn from the study of different models as follows: I. As soon as the understanding of human behavior develops or social conditions change, the model is bound to change. No one model is best for all times. II. Models of organizational behavior are relat
In the numeric pyramid to which tropic level does base always refer?
What do you mean by the term primary or central lymphoid organs? Briefly illustrate it.
Give a brief explanation of cell cycle.
Name the three main arthropod groups characterized according to the presence of antennae? Answer: The Crustaceans contain two pairs of antennae; insects have one pai
18,76,764
1936382 Asked
3,689
Active Tutors
1431810
Questions Answered
Start Excelling in your courses, Ask an Expert and get answers for your homework and assignments!!