In mitochondria, protons accumulate in the

Step-by-step solution

During the passage of two electrons from one an electron carrier (NADH) to another on ETC, enough energy is liberated that pumps out three pairs of protons ( H ⁺ ) from matrix (inner chamber) to outer chamber (inter membrane space) of mitochondria. The accumulation of protons in inter membrane space results their higher concentration than in the matrix creating a proton gradient ( pH ) and electric potential ( ) across the membrane.