flow of protons across an electrochemical gradient flow of tRNA across an electrochemical gradient exposure of ADP to electromagnetic waves exposure of carbohydrates to electromagnetic waves
Which process drives most of the ATP synthesis in a chloroplast?

Options:
- flow of protons across an electrochemical gradient
- flow of tRNA across an electrochemical gradient
- exposure of ADP to electromagnetic waves
- exposure of carbohydrates to electromagnetic waves

flow of protons across an electrochemical gradient