although both enzymes are mitochondrial , glycerol phosphate dehydrogenase resides on the outer surface of the inner membrane and responds to sarcoplasmic changes in ca2+ concentration ( i.e . an increase during contraction ) , whereas the isocitrate dehydrogenase resides in the matrix of the mitochondria and responds to intramitochondrial concentrations of ca2+ ( i.e . a decrease during contraction ) .
C0026237
mitochondrial
C1510421
matrix of