Subject/Course Title: Biology
Unit Title/Skill Set: 4.
Homeostasis and Transport
Overview: This unit examines the structures and mechanisms involved in the transport
of materials across membranes and resulting effects on homeostasis in living things.
Unit Essential Question(s): How do organisms maintain a biological balance between
their internal and external environments?
Unit Key Questions as Do Now’s:
1. Describe how the structure of the plasma membrane allows it to function as a regulatory structure and/or
protective barrier for a cell.
2. Compare and contrast active vs. passive transport mechanisms.
4a. Describe how membrane-bound cellular organelles facilitate intracellular transport of materials.
4b. Explain mechanisms organism use to maintain homeostasis.
What You Need to Know—Answers go on the Reading Guide









Chemical structure of the plasma membrane (Phospholipid bilayer)
Fluid mosaic model
Functions of the plasma membrane
Passive transport mechanisms
Active transport mechanisms
o Diffusion
o Osmosis
o Facilitated diffusion
Active transport mechanisms
o Pumps
o Endocytosis
o Exocytosis
Endoplasmic reticulum
o Rough ER
 Synthesis/transport of proteins
o Smooth ER
 Synthesis/transport of lipids
 Synthesis/transport of carbohydrates
Golgi apparatus -- processes and packages for intra and extra-cellular transport
Examples of Mechanisms
o Thermoregulation
o Water regulation
o Oxygen regulation
o Chemical regulation
 pH/Buffers
 Hormone
 Electrolyte
HOMEOSTASIS AND TRANSPORT SYLLABUS
1.
2.
3.
4.
5.
Day
1-2
Every reading assignment is expected to be completed BEFORE you come to class. Confused
about the reading? Prepare questions to ask in class AS YOU READ.
Be a Scout and Be Prepared…Reading quizzes may be given at ANY time.
Homework is due ON THE DUE DATE (Sectionals—Turn in on the due date…Field trips
and illnesses—turn in on your first day back.).
Do Now’s are to be completed in class and turned in THAT BLOCK. (Absent??—Turn in
first day back. Questions on the reading that goes with the Do Now??—Turn in written
question specifying what you don’t understand. Be specific. Don’t say, “I don’t get it”.)
Vocabulary understanding is necessary. Attend to the words at the beginning of each
chapter, or words that you encounter that are new to you.
Lesson
Slides—Diffusion/Osmosis
Lab—Movement through a membrane-set up
the lab
Chemical Structure of Phospholipid bilayer
Fluid mosaic model
Functions of the plasma membrane
3
Slides—Passive transport
Lab—Check lab results
Homework/Due
Read: p.60-61 The Cell Membrane
Read: Ch 4.1 Cells and Their
Environment
Read: Ch 4.2 Active Transport
Read: p.888 Gas Transport
*Day 2-Slide answer check
Read: p.63-64 Ribosomes and the
ER
Read: p.8 Homeostasis, p.30,
Storage of Energy, p. 40 Enzymes,
p.561 Guard Cells and Transpiration,
P.849 Endothermy
*Slide answer check
4
Slides—Active Transport
Lab—Data analysis
Endoplasmic reticulum, Golgi body
Homeostasis mechanisms
*Slide answer check
5
USA TestPrep Quiz
(Test will be day 3 of next unit.)
DUE: Vocab Game,
Lab, Slide handout,
Do Now’s.
HOMEOSTASIS AND TRANSPORT VOCABULARY
active transport
Golgi apparatus
carrier/transport protein
homeostasis
concentration gradient
intracellular transport
diffusion
osmosis
endocytosis
passive transport
endoplasmic reticulum
phospholipid bilayer
equilibrium
plasma membrane
exocytosis
pumps
facilitated diffusion
selectively/semi- permeable
fluid mosaic model
vesicles
Vocabulary Instructions:
1. On your answer sheet, make a master list of categories to which each of these
words belongs. For example, Golgi apparatus is a cell organelle, so I would make
a category for ‘Organelle’ and place the Golgi apparatus in that list. Fluid mosaic
model describes the cell membrane, so I would make a category for ‘Membrane’
and place that word in it.
2. Divide a plain piece of paper into the number of categories you’ve created,
making a square for each category.
3. Label the category with its name in heavy black print and underlined at the top
of the square.
4. With another plain piece of paper, fold in half length-wise (hot dog). Now fold it
into half. Now fold it into half again.
5. Do the same folding with two more pieces of paper.
6. Make these into flashcards with the word on one side, definition on the other.
Observing Osmosis
In this activity, you will investigate the affect of water on objects, using gummy bears.
Question: What effect, if any, does soaking Gummy Bear candies in water have on
the size of the candy?
1. Prediction: Using a sentence that restates the question, write your prediction on your
answer sheet based on the knowledge you already have and what you know what gummy
bears are made out of.
2. Before you continue, read the activity.
3. Procedure:
a. Make the title: ‘Before and After Gummy Bear Lab’.
In the ‘Before’ boxes:
b. Fill in your data table with the height and mass of your candy bear.
c. Record descriptive observations about the candy bear.
Get a beaker and:
d. Put your candy bear in a container with water covering the bear and set the
container aside until the next day.
The next day:
e. After the candy bear has been in the water overnight, gently take it out of the
water and pat it dry with a paper towel. Be very careful because the candy may be
extremely breakable.
f. Fill in your data table with the ‘After’ height, width, mass, and descriptive
observations.
4. Calculate the following percent changes in the size of the candy and record in the
appropriate spaces:
% change in height
% change in width
% change in mass
**Percent change = (After soaking measurement - Before soaking measurement/
Before soaking measurement) x 100
**Make sure to label your answer with correct units
5. Graph the percent changes on a bar graph. Remember to title and label both axes on
your graph.
6. Look over the following information and use the vocabulary words to answer the
questions below.
Diffusion is defined as the movement of molecules from an area of high concentration to
an area of low concentration.
The diffusion of water molecules through a selectively permeable membrane is known
as osmosis.
Selectively permeable means that some molecules can move through the membrane
while others cannot.
Movement through membranes is called transport.
Diffusion and osmosis are passive forms of transport; this means that they do not need
energy to move from areas of high concentration to areas of low concentration.
Active transport requires energy to transport molecules from low concentration to high
concentration.
Discussion Questions:
a. What happened to the candy after soaking in water overnight?
Use evidence from your lab.
b. Explain why you got these results?
c. What do you think would happen to the candy if you let it soak in a higher
sugar concentration solution? Explain your answer.
Homeostasis and Transport Guided Reading
______Score
Name___________________
Date___________ Blk____
1. Directions: After reading about the cell membrane, do A or B.
A. Make a model of the phospholipid bilayer (Title and labels). Clearly mark the
outside of the cell and the inside of the cell. A confusing issue with the model in
the book is that student often think that the space between the double layer of tails
is the inside of the cell. This is not the case. Make a model of just the heads and
tails that would represent a cut-away diameter view for half of a cell.
OR…
B. Use Fig 11, p.60 to make a model of just the middle view (phospholipid bilayer)
and the blow-up of the head and tail portion on the right (Title and labels).
Discuss the importance of:
a. polarity in regards to hydrophobic/hydrophilic orientation
b. membrane proteins
c. how the membrane is ‘fluid’
a.
b.
c.
Homeostasis and Transport Guided Reading
Page 2
2. Directions: After reading 4.1, do A or B.
A. Make a model of: Fig 1, Fig 2, Table 2, Fig. 3, Fig 4 (you don’t need as much
detail as the text models have) in the left box. Don’t forget Title and labels).
Write a summary sentence for each explaining what is happening in the right
box.
OR…
Homeostasis and Transport Guided Reading
Page 3
B. Make a Venn diagram showing the relationship between diffusion, osmosis,
facilitated diffusion, diffusion through ion channels. Remember that a Venn
diagram has a central region showing what all the parts have in common, and then
regions that extend outward showing what is different about each of the parts.
Don’t forget a Title.
Homeostasis and Transport Guided Reading
Page 4
3. Directions: After reading 4.2, Active Transport, do A or B.
A. Do the Section 4.2 Review questions 1, 3, 5.
B. Do the Section 4.2 Review questions 2, 4, 6.
Homeostasis and Transport Guided Reading
Page 5
4. Directions: After reading about the Golgi apparatus and Endoplasmic Reticulum, do A
or B.
A. Discuss how structure is related to function in the rough ER, the smooth ER and
the Golgi apparatus.
B. Make an outline of your reading (you don’t need complete sentences in an
outline). Include statements, supporting evidence, and a model of each structure.
Homeostasis and Transport Guided Reading
Page 6
5. Directions: After reading about homeostasis in various examples of organisms, write
an infomercial with supporting evidence and a model explaining why this is such an
important concept. Use at least 6-8 sentences. Remember what a model needs????
Homeostasis-Osmosis Do Now’s
_____________Score
Day
1
2
4a
4b
Name__________________________
Rephrased question and answer, in a sentence, with punctuation.