Chapter 4, Problem S2.6BYB

Summary Introduction

To understand:

The reason that the structure of a phospholipid makes it an ideal molecule for the plasma membrane.

Introduction:

Phospholipids are regarded as the major class of membrane lipids. They are found in abundance in the membranes. It is made of four components including one or more fatty acids, a platform to which fatty acids are attached, a phosphate, and an alcohol attached to phosphate.

Explanation of Solution

Phospholipids are an ideal molecule for the plasma membrane because of the presence of many extensive properties like the feature of enclosing and forming compartments. The difference created between intra and extracellular compartments is because of the structure of phospholipid.

Apart from this, if any hole occurs in the lipid bilayer due to any energetic reasons, then it has the capacity to recover quickly. Additionally, they form sheet-like structures which are electrically polarized on the membranes. It makes the membranes amphipathic which have both polar and non-polar properties. Specific proteins are present on phospholipids which make and promote the functions of the membrane. These proteins functions as pumps, channels, energy transducers, enzymes, and receptors.

Furthermore, the phospholipids are an ideal molecule for the membrane because of other reasons like keeping the membrane together due to hydrophobic forces or non-covalent assemblies. Other than this, the phospholipids do not allow the movement of any substance across membrane except water and gases. Phospholipids help in balancing the water and other organic molecules from the influx and efflux through the cell as well as environment.

The lipid bilayer comprises lipid molecules and proteins and is highly fluid in nature which helps in the mobility of these structures. The fluid nature influences the membrane transport.

Conclusion

The understanding of the phospholipid in context of plasma membrane reveals that it is the lipid bilayer which supports the membrane and makes it worth functioning. The several features like the formation of the compartment, assembly of proteins, non-permeability, and others make it an ideal molecule for plasma membrane.