Answer:
Many cellular processes use similar mechanisms to achieve different goals.
Explanation:
<em>Metabolic pathways are series of enzyme-catalyzed reactions. Enzymes interact to remove and add phosphate groups to molecules or to move protons across a membrane. The same as in cell signalling, where the receptor proteins interact with specific molecules and often remove or ad phosphate groups. The phosphorylation of receptor proteins is very close to the process steps in metabolic pathways but with a very different function. </em>
<em>In metabolism phosphorylation is a method of transferring energy, in cell signalling it transmits information.</em>
The correct answer is the third one
Magnetic Field of a magnet is the strongest part
