Chapter 2, Problem 1RTC

Summary Introduction

(a)

To write:

About the advantage of stickiness method over the covalent interaction for the gecko reptile.

About the effect of the van der Waals force that helps the gecko to stick its feet.

Introduction:

A reptile known as gecko has an ability to climb through the smooth surfaces that follows van der Waals interactions between its feet with septa and the smooth surface when it climbs.

Explanation of Solution

One of the most important biological process which is the covalent bond consumes much of energy to form it. The other process which is the van der Waals interaction takes less energy compared to this covalent interaction. So when the reptile tries to use the covalent bond interaction to stick the septa on the surface, it will require more energy and also it would make the reptile to move very slowly. Unlike the covalent interaction, the van der Waals interaction has a weak bond and the reptile requires less energy to break this bond. So using this van der Waals interaction which acts between the feet and the smooth surface, gecko the reptile can move faster and easily.

Though the van der Waals forces are weak, they become strong when the gecko reptile uses this force having many septae on its feet. This septae are individual pads that are small in size and when each such tiny pad uses this weak force, they become strong collectively. Covalent bond is not as effect as this van der Waals force as they are strong individually requiring lots of energy to break the strong bond while the reptile climbs.

Conclusion

Thus, the covalent bond which is stronger do not help the reptile to glue its feet on the smooth surface whereas the van der Waals bond being a weak force enables the reptile to stick its feel to the surface while climbing.