Final answer:
The inner matrix of mitochondria is negatively charged, and the intermembrane space is positively charged, contributing to ATP synthesis on the inner mitochondrial membrane during cellular respiration.
Step-by-step explanation:
The inner matrix of the mitochondria has a negative charge, while the inter-membrane space has a positive charge. This charge gradient is crucial for the process of ATP synthesis that occurs on the inner mitochondrial membrane. The cristae, which are the folds in the inner membrane, increase the surface area for this process.
The second stage of cellular respiration, the Krebs cycle, takes place in the matrix, and the third stage, electron transport, occurs on the inner membrane.