WARM UP: Tues, Oct 1
• In your 3 brad folder:
• Define homeostasis in your
own words.
(Hint: look in cell theory notes)
Cellular Processes
Day 1
Objectives
1. Define homeostasis.
2. Describe the Fluid Mosaic Model.
3. List items that enter & exit the cell .
Homeostasis
= ability to maintain internal equilibrium
– Maintain = keep
– Internal = inside
– Equilibrium = stable or balanced
Why is maintaining homeostasis
in our body & cells important?
An imbalance =
disease or death!
Cell Membrane
• Function:
1) Regulates what enters & exits cell
2) Provides protection & support
Cell Membrane AKAs
• AKA: Plasma Membrane
• AKA: Phospholipid Bilayer
• AKA: Fluid Mosaic Model
Fluid Mosaic Model
• Fluid = not solid, membrane moves
• Mosaic = made of many parts
Parts of a Plasma Membrane
• Different Macromolecules in membrane:
1) Lipids = create bi-layer
2) Protein = create channel to pass large items
3) Carbohydrate Chains = identifying markers
A Closer Look at the Cell
Membrane
Lipid Bi-Layer = 2 layers
Phosphate head
Fatty Tails
Phospholipid Bilayer
• Phospholipid = hydrophilic head +
hydrophobic tail 
BILAYER
• Hydrophilic = water loving
• Hydrophobic = water fearing
• Water & Oil do not mix
Latin Root: Bi = 2
What Enters?
• What the cell needs for survival
1)
2)
3)
4)
Nutrients
Water
Oxygen
Nucleic Acids (blueprint)
What Exits?
• What the cell needs to remove for survival
(wastes)
1)
2)
3)
4)
Carbon Dioxide
Excess water
Urea
Other cellular wastes
Membranes
1) Permeable = anything can cross
2) Impermeable = nothing can cross
3) Selectively Permeable = some
substances can cross, but not others
AKA Semipermeable
***Most membranes are selective***
Phospholipid Bilayer and
maintaining homeostasis
• Keep Balance = membrane selectively
permeable
ENTER
NO ENTRY
Egg Lab: Day 1
1. Paste chart onto spare
sheet of notebook paper
you picked up at the door
2. Write your name, date, and
period at top right corner of
notebook paper
3. Hypothesis: I believe the
egg shell will _______ with
vinegar.
Egg Lab: Day 2
Answer questions 1-2 in complete
sentence
Hypothesis Day 2: “ I believe…”
- Will the syrup level go up or down?
- Will the egg get larger or smaller?
WARM UP: Wed, Oct 2
• In your 3 brad folder:
• What is the difference between
a permeable and impermeable
membrane?
Cellular Processes
Day 2
Objectives
1. Define diffusion & osmosis.
2. Explain the 3 types of osmosis.
3. Define osmotic pressure.
4. Predict the results of an osmotic lab
experiment.
How “things” get selected to
come into and out of the cell…
PASSIVE TRANSPORT
DIFFUSION
OSMOSIS
DIFFUSION
= movement of particles
from high to low
- Goes w/ the crowd
- w/ the concentration
gradient
• Does NOT require energy
• Diffusion stops when 2
areas are EQUAL
(homeostasis)
Low
High
Facilitated Diffusion
= movement larger molecules w/ “help” from
protein channels
• Does NOT require energy
OSMOSIS
= diffusion (movement) of water
- From high to low
- W/ the crowd
- Does NOT require energy
Solvent & Solute
• Solvent = the liquid portion
– i.e. the water in a salt water
mixture
• Solute = the part that is
mixed in
– i.e. the salt in a salt water
mixture
3 Types of Osmosis
1) Hypertonic Solution = > (greater)
concentration of solute outside the cell
than inside
- Cell Shrink
Latin root: Hyper = over, more, higher
3 Types of Osmosis
2) Hypotonic Solution = < (lower)
concentration of solute outside the cell
than inside
- Cell Burst
Latin root: Hypo = under, less, lower
3 Types of Osmosis
3) Isotonic Solution = concentration solute
outside = concentration inside
- Cell stays the same
Osmotic Pressure
= pressure exerted on a cell membrane
due to concentration gradient
= different conc. on either side of the
cell membrane
Egg Lab: Day 2
Answer questions 1-2 in complete
sentence
Hypothesis Day 2: “ I believe…”
- Will the syrup level go up or down?
- Will the egg get larger or smaller?
Egg Lab: Day 3
Answer questions 3-7 in complete
sentences
Hypothesis Day 3: “I believe…”
- Will the water level go up or down?
- Will the egg get larger or smaller?
WARM UP: Thurs, Oct 3
• In your 3 brad folder:
• What is the difference between
a hypertonic solution & a
hypotonic solution?
Cellular Processes
Day 3
Objectives
1. Define active transport.
2. List the types of active transport.
3. Define concentration.
4. Predict the results of an osmotic lab
experiment.
Osmotic Pressure
= pressure exerted on a cell membrane
due to concentration gradient
= different conc. on either side of the
cell membrane
Active Transport
= movement of molecules against the
concentration gradient
***Low to High***
– Against the crowd
– REQUIRES energy
– ATP = energy in cell
Requires
Energy
ATP
Endosytosis
= take materials into cell
Latin root: endo = inner
Endosytosis
• Type 1:
Phagosytosis
= engulf and ingest
particles
= “cell eating”
- EX: white blood
cells eating
invading bacteria
cells
Endosytosis
• Type 2: Pinocytosis
= ingest extracellular
fluid & its contents
= “cell drinking”
– EX: human egg cells
drinking nutrients
from surrounding cells
while maturing in
ovary
Exosytosis
= cell releases materials to the outside
- discharge as membrane-bounded vesicles
- pass through the cell membrane
= “out of the cell”
Latin root: Ex = outer, away from
Egg Lab: Day 3
Answer questions 3-7 in complete
sentences
Hypothesis Day 3: “I believe…”
- Will the water level go up or down?
- Will the egg get larger or smaller?
WARM UP: Fri, Oct 4
• In your 3 brad folder:
• Define the term equilibrium
Egg Lab: Day 4
- Answer questions 8-12 in
complete sentences
Friday, Oct 4
• Periods 1, 2, & 5 = Cell Process
worksheets
WARM UP: Mon, Oct 7
• In your 3 brad folder:
• What are the 3
macromolecules found in the
plasma membrane?
WARM UP: Wed, Oct 9
• In your 3 brad folder:
What type of active transport is
shown in this diagram?
Cellular Processes
Day 4
Objectives
1. Describe the difference between positive
(+) and negative (-) feedback.
2. Define solution & concentration
3. Define concentration gradient.
Solution & Concentration
Solution = mixture 2+ substances
Concentration = amount of substance
(solute) in liquid (solvent)
– Cytoplasm = one concentration
– Outside of cell = another concentration
*** Want balance (homeostasis)***
Concentration
• Concentration gradient = unequal
distribution on either side of a membrane
• Equilibrium = concentration same on both
sides of cell
Feedback Mechanism
= loop system in which system responds in
either:
1) same direction (positive feedback)
2) opposite direction (negative feedback)
Feedback Mechanism
Feedback Mechanisms
• Channels = allows larger particles to
come in. (Gate/Door)
• Receptors = signal (Intercom)
• Markers = identify the type of cell
(ID Badge)
Positive Feedback
= results in amplification or growth of output
signal
• Ex: If you eat a McDouble at McDonalds, a
hormone is released to your brain to signal
satiation. You will feel the same
“happiness” each time you eat the
hamburger.
Negative Feedback
= results in system responding in the
opposite direction
• EX: Regulation of blood glucose levels.
– Blood glucose levels continue to rise
– May result in diabetes
• EX: Sweating
Egg Lab: Day 4
- Answer questions 8-12 in
complete sentences
Feedback Research
1. Using a laptop, research an example of positive or
negative feedback.
2. Use the next blank page in your spiral to write a 6-8
sentence summary of the article you found. Be sure to
write if it is a POSITIVE or NEGATIVE feedback.
3. Write the website that you found your information from
at the bottom of your page.
4. This will be worth 4 stamps.
Login: first 5 letters of last name; first 3 letters of first name; 000 ( try
001 if you have the same name as someone else in the school)
Password: student ID #
Avid Thinking Strategy
• Map News! Page 9 #19
How does this
Affect me?
New
Vocabulary
Name of
Source
Date
Title of News Article or
Topic
Branch of
Science
Clues
Evidence
Science
Fact
Conclusion
WARM UP: Tues, Oct 8
• In your 3 brad folder:
1) List two types of passive
transport.
2) Is the movement from high to
low or low to high w/ passive
transport?
Tues, Oct 8
Latin Roots Quiz
& Osmosis/Diffusion
Worksheets
Latin Roots Quiz
1.
2.
3.
4.
5.
Bi = ______
Mono = _____
Bio = ______
Poly = ______
Di = ________
Bonus: Cyto = ______
6. Macro = _____
7. Endo = ______
8. Hypo = ______
9. Hyper = _____
10. Ex = _______
WARM UP: Wed, Oct 9
• In your 3 brad folder:
What type of active transport is
shown in this diagram?
Wed, Oct 9
Stations Review
WARM UP: Thurs, Oct 10
• In your 3 brad folder:
• What process is shown in the
diagram?
Thurs, Oct 10
Gems of Wisdom
WARM UP: Fri, Oct 11
• In your 3 brad folder:
• Define the term positive
feedback and give an
example.
Fri, Oct 11
Test
Alternate Assignment for
Field Trip
1. Research a saltmarsh &
wetlands habitat.
2. Look up the Galveston Bay
Foundation & their Hip to
Habitat program.
3. Write a 2 page essay on how GBF helps
preserve/restore saltmarsh habitat in our
area.