Chapter 7, Problem 35A

Summary Introduction

To determine:Difference between hypertonic and hypotonic solution and how these two are related.

Introduction:

The Outermost layer of plant cell is cell wall. The behavior of the plant cell depends on the surrounding environment with regard to movement of water.Osmosis can be defined as the process by which molecules tend to pass through semi-permeable membrane from less concentrated solution to more concentrated solution. Tonicity can be defined as the relative concentration of solutes dissolved in solution which determine the direction and extent of diffusion.

Answer to Problem 35A

Hypertonic and hypotonic both terms are related to tonicity and osmotic pressure. Cellswells up when placed in hypotonic solution and shrinks when placed in hypertonic solution.

Explanation of Solution

There are three types of osmotic solutions named isotonic, hypotonic and hypertonic solution.

A hypotonic solution has a lower concentration of solutes than another solution. Solution outside of a cell is called hypotonic if it has a lower concentration of solutes relative to the cytosol. Due to osmotic pressure, water diffuses into the cell, and the cell often appears turgid, or bloated.

A hypertonic solution has a greater concentration of solutes than another solution. When a cell is placed in a hypertonic solution, water moves out of the cell and the cytoplasm get shrink as osmotic pressure tends to force water to flow out of the cell in order to balance the concentrations of the solutes on either side of the cell membrane.

In isotonic solution, the concentration of the surrounding environment is exactly same as the concentration of the cytoplasm so the net movement of water is zero.