2018 Fall.Includes bibliographical references.There are many types of molecules that interact with and within membranes whereas many factors can dictate how they interact with membranes. Often, the interactions with the membrane interface can affect the mechanism of action of these molecules. Here, the interactions of small molecules and an electron transporter with model membranes under varying conditions are described. In the first chapter, the pH dependence of membrane association of a commonly used food preservative, benzoic acid was discussed and compared to the mechanism of action of general weak acid preservatives. Next the interactions of many structurally very similar compounds with model membranes were compared. These studies outline the importance of both the environment and that by just altering the molecules slightly, the interactions of the molecules can be changed. Chapter 4 outlines the importance of lipid density on the interactions of the electron transporter used within the electron transport system of Mycobacterium tuberculosis (menaquinone-9) to show that menaquinone is capable of membrane transport of protons and electrons. Together, these studies show how interactions and diffusion across membranes are not straight forward and more research is necessary to fully understand the interactions of molecules with cell membranes
