Biomembranes are extensively inhomogeneous with respect to the compositions and distribution of the lipid molecules constructing them. The lipidome of a cell and its sub-cellular distribution constitute a nonequilibrium condition maintained by i) active expenditure of cellular energy and ii) coordination of metabolic/transport processes. Though there is lipidomic/bioinformatic evidence suggesting that the above interplay is relevant for the integration of membrane biology and lipid metabolism, the thermodynamic premises underlying a hypothesized, regulatory framework have not been rigorously tested. Moreover, the role of bilayer lipid asymmetry- referring to lipid inhomogeneity between the leaflets of a lipid bilayer- has been ignored in this context. Since bilayer lipid asymmetry is a ubiquitous feature of biomembranes across cellular life, it is likely important for membrane homeostasis, necessitating further investigation. To investigate how bilayer lipid asymmetry might serve the above role, this thesis describes observations in vesicles along with a thermodynamic analysis. These were achieved by leveraging complexation between methyl-β-cyclodextrin (mbCD) and phospholipid molecules, which adjusts the difference in the number of lipid molecules (lipid number-difference) between the leaflets of vesicles. This parameter constitutes one contribution to bilayer lipid asymmetry and mbCD-lipid complexation allowed its effects upon i) vesicle morphology, ii) bilayer phase behavior, and iii) lipid thermodynamics to be investigated. Evidence suggests that lipid number-difference modulates the chemical potential (and activity) of lipids within a bilayer. Then, to investigate generation of lipid number-difference by a transmembrane protein, an active phospholipid transporter (a flippase) of the ATP-binding cassette transporter superfamily was purified and reconstituted into a bilayer environment. This was done to eventually investigate the i) conformation and ii) catalytic efficiency of flippases in this superfamily with respect to lipid number-difference (by leveraging mbCD-lipid chemistry). Challenges encountered during purification/reconstitution are described and recommended actions proposed. Achievement of the aims associated with these efforts could contextualize i) the allosteric regulation and ii) energy transduction of such proteins within a control scheme for maintenance of embrane homeostasis.