DATE:
CHAPTER 2
SKILL BUILDER
Goal
NAME:
COMPARING DIFFUSION, OSMOSIS, AND ACTIVE
TRANSPORT USING A VENN DIAGRAM
CLASS:
BLM 2-7
Ÿ USE THIS PAGE TO DEVELOP YOUR UNDERSTANDING OF DIFFUSION, OSMOSIS, AND ACTIVE
TRANSPORT BY DEVELOPING A VENN DIAGRAM.
What to Do
1. Look at the Venn diagram below. Carefully read all the labels and questions.
2. Compare diffusion, osmosis, and active transport by filling in the different sections of the Venn
diagram. Use the questions with the arrows to help you to fill in the overlapping regions of the
diagram.
What do diffusion and osmosis share?
DIFFUSION
OSMOSIS
•
Movement of particles
from high to low
concentration.
•
Deals with the movement
of SOLUTE in a solution.
No energy
required,
spontaneous
and random
movement.
Particles
moving in
and out of
cells.
What do diffusion and
active transport share?
Particle
Theory
•
Movement of water from
high to low concentration.
•
Deals with the movement
of SOLVENT (water) in a
solution.
Particles
moving in
and out of
cells.
•
Movement of particles from low to
high concentration.
•
Requires energy.
•
Requires the use of carrier proteins.
ACTIVE TRANSPORT
What is common
between all three?
What do osmosis and
active transport share?
Check Your Understanding: Diffusion, Osmosis, and Active Transport
1. What process causes water to enter or leave a cell?
The process that causes water to enter or leave a cell is called OSMOSIS.
2. How are osmosis and diffusion alike? How are they different?
Alike: Both osmosis and diffusion involve the movement of particles from an area of high
concentration to an area of low concentration, and neither process requires energy.
Different: Osmosis is the movement of water particles specifically, while diffusion is the
movement of any particles.
3. How is active transport different than diffusion? Give an example of each.
Active transport is movement of particles AGAINST a concentration gradient. This
means the particles move from an area of low concentration (where they are not crowded)
to an area of high concentration (where they are crowded) – this process requires a lot of
energy, and the help of carrier proteins to move particles across the cell membrane! In
contrast, diffusion is the movement of particles ALONG a concentration gradient. This
means the particles move from an area of high concentration to an area of low
concentration – this process does not require energy, and happens spontaneously.
4. If your teacher opens a bottle of perfume at the front of the classroom, you will smell the
perfume at the back of the room a short time later. Explain what has happened here.
What has happened is that the perfume particles have diffused through the air in the
classroom. The air particles are constantly moving and vibrating, so when the perfume
particles are released into the air, they bump into these air particles. All of the particles
are trying to achieve maximum space, so they continue to bump into each other and move
until they are evenly spread out. This is called diffusion.
5. Apply: Why do grocery stores spray their fresh vegetables with water?
Grocery stores spray their vegetables with water to keep them plump and remaining
fresh. Over time, they will lose water and start to shrivel. By spraying the vegetables with
water, it ensures that water will enter the vegetable cells through the process of osmosis
and keep it looking fresh for longer.
6. Bonus (Thinking Critically): Why will a goldfish die if it is placed in salt water?
The amount of salt in a goldfish may be significantly less than the amount of salt in salt
water. If the inside of the fish cells are considered to contain a “dilute salt solution” and
the surrounding water is considered a “concentrated salt solution”, then water will move
out of the fish cells through the process of osmosis, and into the surrounding water. The
fish requires some water content in its cells in order to survive!