🧪 Scientific Discoveries & Energy REDOX ⚡

8th grade biology

O-18 isotope

Heavy oxygen isotope used to trace the source of oxygen released in photosynthesis

Water

Proven source of oxygen released during photosynthesis

CO₂

Provides carbon and oxygen for sugar, not for released O₂

Melvin Calvin

Scientist who mapped the Calvin cycle using radioactive carbon

C-14 isotope

Radioactive carbon used to trace sugar formation steps

Redox reaction

Chemical reaction involving the transfer of electrons

Oxidation

Loss of electrons from a molecule

Reduction

Gain of electrons by a molecule

Endergonic

Reaction that requires energy input, like photosynthesis

Exergonic

Reaction that releases energy, like cellular respiratio