Diffusion and Osmosis HW

Name: ______Date: ______

Diffusion and Osmosis HW

What happened to dinner?

Jenny’s family planned to attend her brother’s basketball game on a school night. Her mother cooked spaghetti sauce. Jenny offered to make the salad and cook the spaghetti. First, Jenny washed the lettuce. Then, she sliced tomatoes, cucumbers, and radishes. Next, Jenny put some pepper, herbs, oil, and vinegar on the vegetables. Finally, she tossed the salad, covered it, and placed it in the refrigerator. Jenny read the directions for cooking a pound of spaghetti. She was surprised to see that she needed five quarts of water to boil the spaghetti. Jenny read the label on the box and found that the food was made from ground-up plants. Jenny slid the dry spaghetti into the boiling water and waited while it cooked. She drained the spaghetti. It took up much more space now than it had before it was cooked. Almost all the water in the pot was gone. What had happened to the water and the dry spaghetti? Jenny took the salad from the refrigerator. The vegetables were no longer crisp. There was more liquid in the salad bowl than she had added. What had happened to the veggies?

Analyzing the Problem:

1. How did the dry spaghetti increase in size?

Water entered the cells of the spaghetti by osmosis

1. Where did the liquid in the salad bowl come from? (in your answer use the correct word: hypertonic, hypotonic, or isotonic)

The water from the lettuce cells exited them into the bowl because the dressing was hypertonic to the lettuce cells.

3. Label the pictures below (isotonic, hypertonic, or hypotonic environments)

environment is hypotonic environment is hypertonicenvironment is isotonic

Analyze the following situations:

Analyze the experiment below:

Two sides of a container are separated by a membrane permeable to both water and iodine.

BEGINNING OF THE EXPERIMENT: End of the experiment:

6. Fill out the following chart:

Number of Molecules at the Beginning of the Experiment / Number of Molecules at
the End of the Experiment
Left Side / Right Side / Left Side / Right Side
Iodine / 12 / 0 / 6 / 6
Water / 11 / 23 / 17 / 17

7) Did diffusion take place during this experiment? _____yes______Which molecules (water, iodine) diffused during this experiment? ___iodine______

8) Describe the movement of water and iodine molecules during this experiment.

• In which direction did the iodine molecules diffuse? ( left to right , right to left ) circle one
• In what direction did the water molecules diffuse? ( left to right , right to left ) circle one
• Iodine molecules moved from an area of ______(high,low) concentration of iodine to an area of ______(high, low) concentration of iodine.
• Water molecules moved from an area of high ______(water, iodine) concentration to an area of low ______(water, iodine) concentration.

9) At the beginning of the experiment (the first picture), the two sides of the apparatus have differences in the concentrations of solute particles. What is this difference called? ______concentration gradient______

10) What is another term for the type of transport that does not require metabolic energy (ATP)?(circle answer) Passive transport Active transport

11) At the end of the experiment, the solutions were (hypertonic, hypotonic, isotonic) to each other. circle one

12) At the end of the experiment, are molecules of iodine and water still moving? Explain and use the correct vocab term.

____Yes, there is always movement but now it is equal back and forth. This is dynamic equilibrium.______