The objectives of the study of the association of some glycolytic enzymes with membranes include: 1. to investigate and characterize the binding of these enzymes to membranes in cells other than erythrocytes, 2. to examine the possible changes in binding of glyceraldehyde 3-phosphate dehydrogenase to membranes during the maturation of the erythrocyte, and 3. to characterize the interaction of phosphoglycerate kinase with the erythrocyte membrane and investigate the function of the membrane bound enzyme.