Chapter 2, Problem 4AQ

Summary Introduction

To calculate:

The time required by Escherichia coli $(1\times 2\text{μm)}$ swimming at maximum speed (60 cell lengths per second) in order to move all the way up a 3-cm-long capillary tube with a chemical attractant.  

Concept introduction:

Flagella present in a bacteria are thin, long attachments that are fixed into the cell at one end and free at the other end. In Escherichia coli, peritrichous arrangement of flagella is observed. Most of the studies regarding chemotaxis have been carried out in E. coli. Typically, E. coli with flagella distributed all over the surface travel rapidly in a straight line. The force on the cell is produced by rotation of flagellum in a counterclockwise direction. A directed movement away or toward the gradients is termed as taxis. Such movement in response to a chemical compound is referred to as chemotaxis. In the presence of an attractant, chemotactic bacteria tend to travel towards it. Thus, forming a swarm encircling the tip of the capillary tube. Many of the motile bacteria also moves into the tube itself.