Chapter 7, Problem 18A

Summary Introduction

To analyze:

The orientation of the phospholipid in the bilayer allows a cell to intact with its internal and external environments.

Introduction:

The main components of the plasma membranes are phospholipids cholesterol, carbohydrates, and proteins. Carbohydrates are attached to proteins and lipids. Phospholipids are made of glycerol, fatty acids, and phosphate link group.

Explanation of Solution

Plasma membranes are made of two layers of phospholipids. These arrangements are known as phospholipids bilayer. Phospholipids bilayers contain two regions, hydrophilic and hydrophobic.

The hydrophilic head regions are present outside and interact with aqueous fluid both inside and outside the cell. The hydrophobic head contains a nonpolar fatty acid tails. The phospholipids bilayer form barriers between the inner and outer sides of the cell. The other polar or charged substances and water do not cross the hydrophobic core of the membrane.

The phospholipids layers allow to glycolipids, cholesterol, and protein from the channels or gates. Selective permeable of the cell membrane regulates through signal molecules, ions, and macromolecules.

Conclusion

Thus, the phospholipids bilayer arranges with hydrophilic and hydrophobic regions.