Answer:
(B) calmodulin
Explanation:
Calcium in cells acts as second messenger molecule which regulates the very important physiological and cellular process of cell-like neurotransmission, cell migration, secretion, fertilization and many others.
Calcium acts as a messenger by binding to a calcium-binding protein called calmodulin. Calmodulin forms complex with 4 calcium ions through the side amino acids present in the structure of calmodulin.
Thus, calmodulin is the correct answer.
Answer: The SA node
Answer choices are:
<span>A. </span>The AV node
<span>B. </span>The SA node
<span>C. </span>The purkinje fibers
<span>D. </span>The AV bundle
The SA node<span> is the heart's natural pacemaker consisting of a cluster of cells located in the upper part of the wall of the right atrium. (the right upper chamber of the heart). The electrical impulses are produced and sent out from there to regulate heartbeat. This is also called the sinus code. </span>
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