Do Now 1… page
1. How is a plant cell different from an animal cell?
2. What life functions do the following cell organelles carry out?
a)
Mitochondria
b)
Cell membrane
c)
Endoplasmic Reticulum
d)
Ribosomes
3. Where are enzymes synthesized?
4. What makes one protein different from another?
Complete the Cell Membrane Reading
Do Now 2… page
Compound
Starch
Lipid
Enzyme
Big Molecule
Monosaccharide
Amino Acid
Small Molecule
Polysaccharide
Amino Acid
Glucose
Protein
Fatty Acid
Iodine Atom
Cell Membrane
How are things moved within a cell?
How does a cell get rid of waste and take in nutrients?
Hmm…
If a cell needs glucose to make energy, what does the
glucose have to pass in order to get into the cell and to
the mitochondria?
Cell Membrane
Also known as:
Plasma Membrane
Cell Membrane:
Function & Purpose
Cell Membrane
Functions:
 Regulates what enters and leaves the cell (ingestion & excretion)
 Also allows cell communication, identification, and allows the
ingestion and excretion of certain materials
Life Functions = Regulation
,
Excretion
and
Transport
Homeostasis
Helps the cell maintain __________________
by regulating what
enters and leaves the cell.
Cell Membrane only lets CERTAIN
things in and out!
Semi-permeable because it only lets
The cell membrane is _________________
certain substances in and out.
*Regulation
Cell Membrane:
Structure
What are the parts that make up the
Cell Membrane?
Cell or Plasma Membrane is sometimes referred to as a
Phospholipid Bilayer
Why? Lets take a look…
Made of two layers of… Phospholipids
Phospholipid:
 Polar head containing the element phosphorous
 Attracted to water (hydrophilic)
 Non-polar fatty acid tail
 Repels/hates water (hydrophobic)
Phospholipid Bilayer
Why is the membrane a
bilayer?
• Makes it hard for the
membrane to open up /
break
Cell Membrane has more than just
phospholipids…
The cell membrane also has many proteins inside it!
 Help in cell communication and transport
Types of Membrane Proteins
1. Channel proteins
2. Receptors
3. Glycoproteins
Membrane Proteins
1. Channel Proteins (Transport Proteins): Molecules
that are a little to large to pass into or out of the cell
use channel proteins to enter or leave.
2. Receptor Proteins: Transmit information into the
cell by reacting with certain molecules and chemicals.
The part that sticks out has a specific shape and only
molecules with the matching shape can bind to it.
• This is how some pathogens attach to and enter cells!
3. Marker Proteins (Glycoproteins): The name tags of
the cell. Gives each cell its own identity.
Label Your Diagrams!
Cell Membrane: Fluid Mosaic Model
The cell membrane is a thin flexible boundary between the
cell’s internal environment and the outside environment
Fluid – Phospholipids and associated proteins move around like
water in the ocean. The membrane is flexible. (like a bubble)
Mosaic – So many different pieces make the membrane look like
a mosaic or quilt.
Do Now 3… page
Name the molecule or structure:
1. Communicates messages to a cell. Found in the cell membrane.
2. Only 1 atom big and is able to pass through a semipermeable
membrane.
3. Breaks down and synthesizes molecules needed by a cell.
4. Regulates the movement of molecules in and out of a cell
5. This structure allows slightly larger molecules to pass through the
cell membrane.
Cell Membrane:
Transport & Movement
Cell Membrane: Transport & Movement
What is transport?
 The movement of material from one place to another
There are 2 ways that material moves into and
out of a cell:
1. Transport that requires energy (ATP) is known as:
Active Transport
2. Transport that does not require energy is known as:
Passive Transport or Diffusion
Selectively Permeability of the Cell Membrane
Cell membrane DOES NOT let everything in and out
Some materials cross membranes easily:
Small molecules & Compounds water, oxygen,
1. ________________________________:
CO2, amino acids, glucose
Some materials do not cross membranes easily:
Large Compounds Starches, proteins and other
1. ___________________:
macromolecules
Hmm…
Generally, what tells if a molecule will easily pass through
a membrane?
The SIZE of a compound!
But why do molecules move?
Homeostasis
1. The cell wants to maintain __________
– Certain compounds enter the cell in order to maintain a stable
internal environment. For example: if a cell is low on oxygen,
oxygen will move into the cell.
2. Concentration Gradient – Difference in concentration where
High concentration to areas of
molecules move from areas of _______
Equilibrium
Low
________
concentration to maintain a dynamic_______________.
High
Low
Dynamic Equilibrium = Homeostasis
During dynamic equilibrium, molecules are still moving
back and forth across the membrane but at an equal rate.
 Small molecules pass through the cell membrane directly
by squeezing through the phospholipids.
 Slightly larger molecules cannot do this so they must use
__________________
Channel Proteins
DO NOW
Draw arrows and show movement of molecules
**Will the molecules even pass the semipermeable
membrane? Why?
Two types of Transport
1
Passive Transport: No energy required
1. Diffusion
2. Facilitated Diffusion
3. Osmosis
2
Active Transport: Uses energy (ATP) for transport
1. Endocytosis
2. Exocytosis
3 Types of Passive Transport
1. Diffusion
 Diffusion – movement of materials from an area of High
concentration (more molecules in one area) to an area of
Low concentration (fewer molecules in an area)
 Diffusion is used when materials are small enough to
easily diffuse across the membrane.
Diffusion: Before & After
2. Facilitated Diffusion
 Facilitated diffusion – molecules move from areas of high to low
concentration using a carrier or transport protein.
big
 Some molecules, such as glucose, are a little too __________to
pass through the membrane by simple diffusion
Transport proteins
 These molecules need help and use ______________________
to pass through the membrane
3. Osmosis
water from an area of high
 Osmosis – Diffusion of _________
concentration to an area of low concentration.
3. Osmosis
 Water will always move to where there is more dissolved
substance (solute) in water.
 Or, water will move from where it is more concentrated
to where it is less concentrated. To maintain equilibrium
http://www.stolaf.edu/people/giannini/flashanimat/transport/osmosis.swf
3. Osmosis
Practice questions:
1. Cell contains 10% salt and outside the cell contains 20%
salt. Where will water come from and go to?
2. Cell contains 10% salt and the cell is put in distilled
water (100% water). Where will water come from and
go to?
3. Osmosis
Practice question:
3. Kenny was on a boat and forgot to pack water. He made
a bad move and drank salt water from the ocean. What
will happen to the cells in his body?
Practice Problems
4. Why do restaurants soak their lettuce and vegetables in
water before they serve them?!
Which cells are at equilibrium, in slat water
and in distilled water?
A=
B=
C=
Do Now #
Label the cell wall and cell membrane on the plant cell in
the isotonic solution. Second, draw the plant cell when it is
placed in a salt water solution (hypertonic solution)
2 Types of Active Transport
Active Transport
 What is used in active transport that is not used in
passive transport (diffusion)?
 Why would you need to use energy to transport
molecules across a membrane?
Active Transport
• Movement of a substance across a membrane using
ATP
_____.
• This occurs when molecules are moving from areas of
LOW
HIGH
____________
concentration to areas of __________
concentration.
• Active transport occurs through special transport
proteins that push/pull molecules into or out of the
cell using energy
Balloon!
Active Transport
 Where is the concentration highest?
 How would blue diamond get into the
cell?
1. Exocytosis
Exocytosis – type of active transport when large material or
large amounts of material leave the cell. Uses ATP
Example – insulin leaves pancreatic cells by exocytosis
Vacuoles inside cell fuse / connect will cell membrane and
empty contents outside the cell.
Exocytosis
2. Endocytosis
Endocytosis – also known as phagocytosis, this type of
active transport is when large macromolecules or large
amounts of material enter the cell.
• Cell membrane surrounds the macromolecule and creates a
membrane around it.
Practice Problems
What happened to these plant cells?!
Diffusion Lab
Do Now
Predict what will happen in this picture after diffusion
occurs. Focus on the amount of molecules inside and
outside the membrane.
I – Iodine
G – Glucose
S – Starch
What is this lab about?
By the end of this activity you should be able to:
• Demonstrate how to test for simple sugars and starch
using chemical indicators
• Explain diffusion through a membrane
• Describe the permeability of a model membrane for
glucose, starch, starch indicator solution (iodine)
How do we make an artificial cell?
Chemical Testing
Indicator Solution
Used
Material Used
Material Used
Material Used
_________________ _________________ _________________
Distilled Water
Blue-Colored
Glucose Indicator
Solution
Amber colored
Starch Indicator
Solution
Starch
Glucose
What Actually Happened?
 In Cell?
 Outside of Cell?
Before
 In Cell?
 Outside of Cell?
After
Stuff You Have to Know
What are the building blocks of starch?
What is Iodine?
What is a chemical Indicator?
Lugol’s Iodine indicates the presence of _____________
Benedict’s Solution indicates the presence of ___________
Do Now (Lab Part II)
Why would a cell shrivel-up?
What part of the cell would shrivel up?
Explain
Lab… Groups (1)
1. Group 1 – Adriel, Emma, Roberto, Katherine
2. Group 2 – Sebastian, Andreas, Kevin, Caleb, Jose
3. Group 3 – Kaylin, Diamond, Cesar, Wilkin
4. Group 4 – Jordan, Marcus, Jhadith, Eli
5. Group 5 – Danae’, Kevon, Johnelle, Sharel, Matt
These are your groups… NO EXCEPTIONS
Lab… Groups (5)
1. Group 1 – Gabby, Mia, Trayyonna, Jeffrey, Katty, Angel
2. Group 2 – Fallon, Jayln, Brandi, Brendon L, Jendy, Deandre
3. Group 3 – Eddison, Greg, Freddy, Anthony, Brandon G
4. Group 4 – Jada, Trevon, Chelsea J, Laura N, Chelsea R, Nagelis
5. Group 5 – Nyquan, Krystazia, Jakeim, Chris R, Nicole R, Steph
These are your groups… NO EXCEPTIONS
Lab… Groups (8)
1. Group 1 – Denise, Janiya, Jared, Jordan, Niamabi, Kyara
2. Group 2 – Nelgy, Luisa, Jeraldine, Nicole, Pam
3. Group 3 – Lisbeth, Silver, Kris, James, Gianny, Osiris
4. Group 4 – Karla, Ninoska, Keyli, Evelyn, Daniel, Hellin
These are your groups… NO EXCEPTIONS
What to expect
Onion cells in distilled water
What to expect
Onion cells when salt water is introduced
What to expect
Onion cells in distilled water again
Lab DO NOW
Write answers on Loose leaf
1. If an artificial cell with a semipermeable membrane
contained glucose and starch and was placed in
water containing Iodine, what would happen? Why?
2. How can you tell if glucose is present in the water
outside the cell?
3. How can you tell if starch is present in or outside
the cell?
Lab Do Now
What happened to these cells?
What might of caused this?
Lab Do Now
What are the building blocks of starch?
What is Iodine?
What is a chemical Indicator?
Lugol’s Iodine indicates the presence of _____________
Benedict’s Solution indicates the presence of ___________