Diffusion of Agar Cubes
Purpose: Determine which cell size will be
the most efficient at obtaining the most
amount of nutrients or eliminating wastes
Why do cells divide?
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●
●
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Growth
Repair
Development
Reproduction
We need energy, so our cells need
energy:
Cellular Respiration O2 + C6H12O6 → H2O + CO2
Cells take in molecules and release
molecules (in and out)
How does CO2/O2/glucose enter and leave
a cell? Think back to a past lesson…..
What is a ratio? How do you write it?
Question:
What is the ratio of boys to girls in the class?
What is the ratio of brown to black puppies?
The Dimensions:
Area = L x W
Surface Area = L x W x (# of sides)
Volume = L x W x H
Calculate the area and volume for each cube. Remember, always
Include the unit of measure. For area, its is cm2 and volume is cm3.
What is the surface area to volume
ratio of each cube?
Here’s the agar cube →
ar +
P
d ag
e
r
e
d
ow
ter +
wa
d
e
l
l
i
t
dis
lein
hta
p
l
o
n
e
ph
All three agar cubes sat in about 100ml of NaOH. Look at the color of the cubes.
- Why did they turn pink? The agar cubes contained phenolthalien. This is
an indicator that turns a pink color when it reacts with NaOH.
Why did the investigation use phenolthalien?
Let’s Analyze the Results
Calculate the nondiffused area by using
The formula: A=L x W
If you have forgotten what was
done, click on the link to watch the
lab.
Demo Lab