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.
Why is it not accurate to assert that DNA self-replicates?
Explain why allantois is considered as an adaptation to the terrestrial life?
On which organelle of cell structure does intracellular digestion depend? And also write down the chemical content of those organelles.
What is the main difference between the hypothesis-testing and hypothesis-generating approaches to data mining?
Illustrate out the formation of fruits?
Give a brief description of plant transpiration? Write down the two main types of plant transpiration procedure? Which of them is more important in the volume?
ABC analysis: It is an inventory management technique wherein the items are classified and clubbed according to their value. The items including the top 5-10% of the total value of inventory are known as "Class A", next 10-15% is classified as "Class
Write down the parasite which causes giardiasis? How it transmitted and also writes down the typical manifestations of disease?
How do arthropods grow up?
What does Hess law signifies?
18,76,764
1961453 Asked
3,689
Active Tutors
1453888
Questions Answered
Start Excelling in your courses, Ask an Expert and get answers for your homework and assignments!!