wiz-icon
MyQuestionIcon
MyQuestionIcon
1
You visited us 1 times! Enjoying our articles? Unlock Full Access!
Question

Which one is required for muscle contraction and nerve impulse transmission?

A
Ca2+
Right on! Give the BNAT exam to get a 100% scholarship for BYJUS courses
B
Mg2+
No worries! We‘ve got your back. Try BYJU‘S free classes today!
C
Fe2+
No worries! We‘ve got your back. Try BYJU‘S free classes today!
D
Both A and B
No worries! We‘ve got your back. Try BYJU‘S free classes today!
Open in App
Solution

The correct option is A Ca2+
  • A neural signal reaching this junction releases a neurotransmitter (Acetylcholine) which generates an action potential in the sarcolemma. This spreads through the muscle fibre and causes the release of calcium ions into the sarcoplasm
  • Active sites for myosin are present on actin which are masked by troponin-C in resting state. When Ca++ level increases it leads to the binding of calcium with a subunit of troponin i.e Troponin-C on actin(thin) filaments and thereby remove the masking of active sites for myosin.
  • Utilizing the energy from ATP hydrolysis, the myosin head now binds to the exposed active sites on actin to form a cross bridge.
  • This pulls the attached actin filaments towards the centre of ‘A’ band.
  • The ‘Z’ line attached to these actins are also pulled inwards thereby causing a shortening of the sarcomere, i.e., contraction. The myosin, releasing the ADP and P1 goes back to its relaxed state. Hence Ca2+ is required for muscle contraction and nerve impulse transmission.
  • So, the correct answer is 'Ca 2+'.

flag
Suggest Corrections
thumbs-up
0
Join BYJU'S Learning Program
similar_icon
Related Videos
thumbnail
lock
Skeletal Muscle
BIOLOGY
Watch in App
Join BYJU'S Learning Program
CrossIcon