Simplify the following text for a Grade 15 native English-speaking person.
Original: Electron transfer chains ( ETC ) are the cellular mechanisms used for extracting energy from sunlight in photosynthesis and also from redox reactions , such as the oxidation of sugars in cellular respiration .
Simplified: Electron transport chains are the cellular mechanisms used for extracting energy from sunlight in photosynthesis and also from redox reactions , such as the oxidation of sugars ( respiration ) .