Reflection: Checks for Understanding Water on the Move: Osmosis (#1 of 3) - Section 3: Instructional Input/Student Activities

 

Guiding Questions/Decision Tree:

1. What is the water % inside and outside the cell? Are they equal?

2a. If yes, then there is no net movement of water and no real change to the cell system.

2b. If no, then from which direction must the water move to reach equilibrium (out -> in or in -> out)? How much water must move to reach EQ? Student B has jotted down the trick to know what EQ is at the top of the paper. Just one of several viable techniques.

ERROR CHECK: For problem 1-2 (Row #1, beaker #2) the EQ value is not correctly calculated. The total difference between external, internal water is 50%, half of it remains on the outside leading to a proper EQ of 40+25% or 90-25% = 65%. More is needed than simply writing out the formula, huh?

3. What is the physical effect of the cell (shrinks, expands, stays the same)? Student A correctly identifies these but B fails to do any! Student B is a very good student but she must have rushed through it. Success has no shortcuts!

4. Looking at the solute concentration outside the cell, what label applies (hypertonic= more solutes; hypotonic= fewer solutes; isotonic=equal amount)

You can see that both students completed their problem sets by correctly answering all four aspects of the problem solution. And this all started with a basic understanding of the concentration gradient, and adding the concepts of solutes, solvents, and solutions with the goal of reaching equilibrium. Essentially scaffolding from simple (initially known) to more complex (initially unknown).

Student A Osmosis Problems

Student B Osmosis Problems

  Checks for Understanding: Osmosis is simple if you just understand diffusion!
Loading resource...
 

Water on the Move: Osmosis (#1 of 3)

Unit 2: 2) Cells ("Form and Function")
Lesson 14 of 20

Objective: Students will be able to understand the hierarchical nature of multicellular organisms. Furthermore, students will be able to model the process of osmosis and predict and explain its outcomes given the conditions of the environment.

Big Idea: The structure of the cell membrane in addition to specific internal and external conditions dictate how water diffuses sometimes with drastic results!

  Print Lesson
5 teachers like this lesson
Subject(s):
Science, diffusion, cells, form vs. function, Osmosis, Concentration Gradient, permeability, models, cell transport, hierachical organization, scientific conclusions
  60 minutes
spawing
 
1
2
3
4
Similar Lessons
 
Using Analogies to Study the Organelles of the Cell (Day 1 of 2)
High School Biology » Unit 5: A Tour of the Cell
Big Idea: Use student created analogies to deepen their understanding of the organelles in a cell!
  Favorites(8)
  Resources(16)
Walnut Creek, CA
Environment: Suburban
Maria Laws
 
The ABC's of BAF (Brain Anatomy & Function)!
High School Science » Brain Anatomy and Function
Big Idea: Our brain is the computer that runs our body; It has different parts of that function together to execute bodily tasks.
  Favorites(6)
  Resources(26)
Charlotte, NC
Environment: Urban
Tamica Stubbs
 
The Cell Walk (Part 3/3)
Biology » The Eukaryotic Cell
Big Idea: It's Alive! Construct a gym-size model of a cell.
  Favorites(2)
  Resources(40)
Randolph, KS
Environment: Rural
Ruth Hutson
 
Something went wrong. See details for more info
Nothing to upload
details
close