What is the purpose of redox reactions in the cell?

To discharge energy gradually in a step-by-step process.  

Explanation:

The process of cellular respiration comprises various reactions in which electrons are transferred or mediated from one molecule to another. The reactions taking part in electron transfers are called redox reactions or oxidation-reduction reactions.  

With the movement of electrons the energy is released that can be captivated and is used to do work. In cellular respiration, the electrons from glucose move slowly via the electron transport chain ultimately towards oxygen that is, transferring towards lower and lower energy states and discharging energy at each stage.  

igneous rocks are formed by solidification of cooled magma (molten rock), with or without crystallization, either below the surface as intrusive (plutonic) rocks or on the surface as extrusive (volcanic) rocks.  

the composition depends on the source magma. there are almost a thousand types of composition found till now.  

hope this