BIOLOGY LAB (PLEASE READ ALL INSTRUCTIONS BEFORE PLACING BID)

Description

All raw materials and wastes must pass through the plasma membrane of a cell. So how do cells take in the materials they need? In this lab, we’ll explore the processes of diffusion and osmosis, two processes that do not require energy. We’ll also look at the tonicity of fluids and the effects on a red blood cell.

For this lab

• Read pages 25-31 in the Lab Book in Redshelf and use the linked images and video to answer the questions as listed

Exercise 1: Diffusion Through a Semisolid – pages 25-27

Exercise 2: Diffusion Through a Liquid – page 27

• Use the images in the linked PDF below answers the questions for Exercise 1 & 2; pages 25-27.

Exercise 3: Create your hypothesis (Exercise 3 pages 28-29)

• Fill out the prediction chart on page 28.
• What will happen to the egg in the distilled H2O solution? Using your predictions from the prediction chart, write a hypothesis on the top of page 29.
• What will happen with the egg in the Sucrose (sugar syrup) solution? Use your prediction from the prediction chart, write a hypothesis on the top of page 29. (There should be two hypotheses in the box.)
• Watch the Video to answer if your hypothesis was correct and the questions on pages 28-29.
• For the  Table on page 29,  Initial weights:  the  Distilled water egg weighs  82.6  grams initially and the Sucrose egg weighs 83.2 grams .
• Final Weights: After being in the solutions for 1  hour –   Distilled water egg now weighs  85.7 grams and the egg in the  Sucrose ( sugar syrup) solution now weighs  75.6 grams. Calculate the percent change for each.

Exercise 4: Effects of Tonicity and Osmosis on a Red Blood Cell

• Use the Comment Tools and select drawing/pencil to graph and determine the Isotonic point in Red Blood Cells and answer the questions on page 31.
• The graph will also be accepted as a separate computer-created graph or hand-drawn on graph paper. It must be saved as a separate pdf file and uploaded to the submission site along with the Lab 4 pdf.
• The questions on page 31 all refer back to the graph and the information supplied on page 30.