Reference no: EM133198173 , Length: 3 Pages

Lab Report 5: The Passage of Molecules Through Cell Membranes

In the laboratory, we only observed simple diffusion in solutions. Many substances enter and leave cells by diffusion through the plasma membrane. Some substances that diffuse rapidly through a solution may diffuse slowly or not at all through a plasma membrane. What property of plasma membranes might be responsible for this effect?

Slugs are essentially snails without shells. They live in moist environments because they tend to lose large amounts of water through their skin. Large slug infestations can damage plants in a garden or greenhouse. My grandfather told me I could kill slugs by sprinkling salt on them. Why and how does this work?

Today we prevent meat and other foods from spoiling by freezing or refrigeration. Before freezers and refrigerators were widely available, meat was treated with strong saline or sugar solutions (e.g. salt pork or sugar cured ham). The growth of fungi or bacteria on meat is the most common cause of meat spoilage. Freezing and refrigeration produce temperatures at which bacteria and fungi are unable to survive or function well. Explain why salt and sugar solutions can prevent meat from spoiling.

Why do plants wilt? (include osmotic effects on cells in your answer)

In winter we often spread salt on roads and highways to speed ice melting or prevent freezing. In the spring, there is a strip of dead grass several feet wide on each side of the road. What happened?