Question

Hydration and Dehydration (Water and Osmosis) The Berg family went to the community pool to beat the August heat. Everyone was playing hard-swimming, diving, and jumping. After a few hours, the children, Ellie and David, noticed that their fingers and toes were getting wrinkled, just like what happens when they stay in the bath for too long. They wondered why this happens. Ellie's father is a chemical engineer, and he told Ellie that water and dissolved particles were drawn out of her skin by diffusion into the large body of water around her. Her mother is a chemist, and she told Ellie that water was actually drawn into her skin by osmosis. Let's help Ellie and David figure out who is right.

Who was correct? Ellie’s father or mother? Explain the process of getting wrinkly skin and how you know they were correct. Is what happens to skin in an ocean vs. a freshwater lake different or the same? Explain this using concepts and terms learned in this unit.

Answer 1

Wrinkly skin from swimming is caused by osmosis, where water moves into skin cells in freshwater due to a concentration gradient, causing swelling and wrinkles. Ellie's mother is correct, as osmosis explains this phenomenon. Seawater, being hypotonic, may draw water out of the cells, causing less wrinkling, but wrinkling can still occur.

Step-by-step explanation:

The process that leads to wrinkly skin when swimming or soaking in water for extended periods involves osmosis, which is the transport of water through a semipermeable membrane from a region of high concentration to a region of low concentration.

Ellie's mother is correct about this process. When fingers and toes are submerged in water, a concentration gradient is created between the water outside the body and the water inside the body. Since the water outside is purer (has a lower concentration of solutes) compared to the body fluids, water enters the skin cells by osmosis, eventually causing the skin to swell and form wrinkles.

In hydration and dehydration, the balance of water and solute concentration is critical. When our skin is in contact with freshwater, the wrinkling occurs as a result of water moving into the skin, due to the lower concentration of solutes in freshwater. However, in seawater, the high salt content makes it a hypertonic solution compared to our body cells.

So, while freshwater will cause water to flood into the cells, seawater would draw water out, potentially leading to less wrinkling if the solute concentration in the seawater is significantly higher than the body's fluids. However, the same autonomic nervous system response that causes wrinkling in freshwater also occurs in seawater, so wrinkling can still happen.

This phenomenon of wrinkled fingers and toes showcases osmosis in action and underscores the importance of isotonic solutions for cells to function properly. It's an excellent example of how our bodies interact with the environment on a microscopic level through the diffusion and osmosis of water.