Why are oxidation reduction reactions important in cells?

Related questions

• How to balance equations for reduction/oxidation reaction?
• If an electode reaction has dssolved oxygen as a reactant, is the electrode an anode or a cathode?
• If an electrode reaction has dissolved oxygen as a reactant, is the electrode and anode or a cathode?
• What balanced equation represents a redox reaction?
• How are redox reactions involved in electrolysis?
• Why are oxidation reduction reactions coupled?
• What do oxidation reduction reactions involve?
• What are reduction reactions used for?
• What does "calx" mean in oxidation reduction reactions?
• What are the reduced components in this reaction? Zn + 2H(+) → Zn(2+) + H2