23. Lipids

During respiration, oxygen gas diffuses into cells spontaneously. Which type of transport is this?

How would you expect an H⁺ ion to move out of the cell if [H⁺] inside the cell is lower than extracellular fluid?

In oxidative phosphorylation, H⁺ ions from the intermembrane space of mitochondria to the mitochondrial matrix, which type of membrane transport is this?