Chapter 34, Problem 3Q

Summary Introduction

To review:

The relation between the figure of the observations as shown and the table drawn by the researchers.

Given:

The oocytes of the frog Xenopus laevis were taken by the researchers and injected with the messenger ribonucleic acid (mRNA) of plant tonoplast intrinsic protein (TIP). The oocytes of the frog are known to have a larger size and a low osmotic cell permeability. The mRNA of a nontransport protein is also taken by the researchers and injected into the oocytes. Some of the oocytes were kept uninjected by them. These cells were observed after incubating them for 2 days in isotonic medium and then giving treatment with hypotonic solution. The following graph was made by plotting changes in relative volume on the y-axis and time on x-axis:

It was also observed that the oocytes, which had TIP mRNA, burst after sometime while the oocytes, which were injected with a different nontransport protein, and the oocytes which were kept uninjected do not burst. The following table depicts the osmotic water permeability of the three conditions as calculated by the researchers:

Introduction:

TIP is a transport protein present in the tonoplast of the plant cell. It helps in transportation just like the other aquaporins. Osmotic permeability of a membrane is its capability to transport water according to the concentration gradient. The higher the osmotic permeability, more will be the transport of water across the membrane.