DescriptionCholesterol plays a very important part in regulating the properties of mixed phospholipid bilayers. In a human cell, about 50% is covered in cholesterol, and is becoming increasingly important to understand the interactions between cholesterol and the lipid in maintaining properties of the membrane, and in particular its stability more clearly. In an age of increased computer dependence, simulation models based on basic interaction parameters could prove pivotal in advancements in fields such as nano-medicine or monitoring the effect of viruses on cells. In this thesis, a mesoscopic model system of Dipalmitoylphosphatidylcholine (DPPC)-Cholesterol and water, is used to mimic a typical biological membrane. The equilibrium conformation of a membrane requires a tensionless state of the membrane. Depending on the tension, a membrane could either stretch or fold (compression). Simulations using Dissipative Particle Dynamics were used and the concentration of cholesterol was varied and the resulting tension was observed.