Structure of Membranes – Biological Membranes

00:01 The lipid bilayer of a cell's membrane is both the defining boundary and barrier between the cell and the rest of the world around it. In this lecture, membranes will be the subject, and in this talk I will talk about structure of membranes and how they relate to the function. The fluidity of membranes and the importance of fluidity as it relates to temperature. And the transport functions carried out by membranes and why they're important with respect to cellular function.

00:28 Now membranes are part and parcel of every living system. In prokaryotes, membranes are relatively simple because the prokaryotic cell does not have internal organelles, as can be seen in this figure. The prokaryotic cell has a lipid bilayer and it also has a capsular cell wall protecting the cell from the rest of the world. The eukaryotic cell does not have typically, at least in an animal cell, does not have a cell wall that protects it and has a fairly thin lipid bilayer. But in addition to that lipid bilayer forming the cell membrane, there are also internal membranes that cover and protect the individual organelles, such as the mitochondrion, the nucleus, and so forth.