Corrigenda: Goddard, J. D., ”A Fundamental Model for Carrier-Mediated Energy Transduction in Membranes, ” J. Phys. Chem., 89 , 1825-30, 1985. 1. Caption, Fig. 4: ”duoports” should read ”antiports”. 2. Eq. 3.17) should read: ˆ C (K-K ′ )=  R + R ′ + 1 k ′ + 1 k  (K + K ′ )/2+  R ′ + R + 1 k ′  + KK ′ /k +(r ′ - R)(K - K ′ )/2  J 3. Eq. (3.25)should read: a = K +1 K [R + R ′ + 1 k ′ + K k ]/ ˆ C 4. Second paragraph of conclusions: ”specific activity, 36 ” should read ”specific activity 32 ,” 5. Line 10, final paragraph: ”reagents” should read ”reagent”. 1