Fig. 7. Activity of pyruvate kinase (PK) from the mantle and posterior adductor muscle (PAM) of M. barbatus during acclimation to different water temperatures. Activity (µmol min^–1 g^–1 wet mass) was determined at 2 mmol l^–1 (V_max; open circles) and 0.05 mmol l^–1 of phosphoenolpyruvate (PEP; V_o; filled circles). Values are means ± s.e.m.; N=10 preparations from different animals.