Cell specification and the ensueingensuing division of labor enables the accomplishment of complex tasks in multicellular organisms. In plants, mesophyll and guard cells exhibit striking functional, metabolic and mechanophysical differences: mesophyll cells are highly specialized for efficient light-energy conversion, while guard cells regulate gas exchange. Here, we address whether and to what extend the cellular specialization is sustained by mitochondrial diversity between cells. We developed mRACE (RApid CEll-type specific isolation of mitochondria), an innovative method for rapid cell-type-specific mitochondrial isolation. mRACE involves biotin labeling of mitochondria in target cells, followed by affinity-based organelle enrichment using streptavidin-coated microbeads or immobilization on functionalized glass slides. Using mitochondrial activity modulators, we confirmed that mRACE-isolated mitochondria remain physiologically active, validating their suitability for downstream analyses. Applying mRACE, we isolated mitochondria from mesophyll and guard cells and performed a comprehensive proteome analysis. Notably, guard cells exhibit active branched-chain amino acid (BCAA) catabolism, suggesting they exploit this unconventional carbon source for energy. Additionally, both cell types differ in ribosomal protein composition and RNA-editing proteins, highlighting mitochondrial specialization at multiple regulatory levels.