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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. Describe cell cytoplasm?
Do Now1. How would you create this graph?
11.0
Big Molecule Small Molecule
Polysaccharide
Amino Acid
Glucose
Protein
Fatty Acid
Iodine Atom
Compound MonosaccharideStarchLipid Enzyme Amino Acid
11.1
Cell Membrane How are things moved within a cell?
How does a cell get rid of waste and take in nutrients?
Cell Who?If a cell needs glucose for energy, what does the glucose (needed for energy) have to pass in order to get into the cell and to the mitochondria?
CELL MEMBRANE !!
Also known as:Plasma Membrane
Cell MembraneFunctions:
Regulates what enters and leaves the cell
• Life functions = ____________________________________
Also provides protection, cell communication and identification
Helps the cell maintain __________________ by regulating what enters and leaves the cell.
Only lets certain molecules in and out?
YES!
Therefore, the cell membrane is Semipermeable
What are the building blocks of the Cell Membrane?
Cell or Plasma Membrane is sometimes referred to as a Phospholipid Bilayer
Why? Lets take a look…
Made if many… PhospholipidsPhospholipid:
Polar head containing the element phosphorous that IS attracted to water (hydrophilic)
Non-polar fatty acid tail that repels/hates water (hydrophobic)
Phospholipid Bilayer
Why is the membrane a bilayer?
There was more stuff in the membrane than just phospholipids
Good looks! The cell membrane has many proteins throughout it.
-- Help in cell communication and transport across the membrane
Membrane Proteins1. Channel Proteins (Transport Proteins): Act as a
passage way where only certain molecules can pass. Molecules needed by the cell cross the membrane through these channels.
2. Receptor Proteins: Transmit information into the cell by reacting and “welcoming” certain molecules. The part that sticks out has a specific shape and only molecules with the matching shape can bind to it.
3. Marker Proteins (Glycoproteins): The name tags of the cell. Gives each cell its own identity.
Membrane Proteins
1. Receptors2. Channel proteins3. Glycoproteins
Cell Membrane: Fluid Mosaic Model Are all the pieces of the membrane set in place?
Fluid – Phospholipids and associated proteins move around like water in the ocean. The membrane is flexible. Mosaic – So many different pieces make the membrane look like a mosaic or quilt.
Label Your Diagrams!
Do NowName 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. Made of amino acids, this structure allows slightly larger molecules to pass through the cell membrane.
Cell Membrane Structure What are these cell membrane structures?
Cell Membrane and TransportWhat is transport?
The absorption and movement of material from one place to another.
Many ways materials move into and out of the cell
Transport into or out of cell that requires energy (ATP) is known as: ________________________
Transport that does not require energy is known as ________________________
Selectively Permeability of the Cell Membrane
Cell membrane does not let everything in and out
Some materials cross membranes easily: 1. Lipid molecules (non-polar molecules) 2. ________________________________: water, oxygen,
CO2, amino acids, glucose
Some materials do not cross membranes easily:3. ________________________________: Starches,
proteins & some charged (polar) molecules
Hmm…
Generally, what tells if a molecule will easily pass through a membrane?
Why do molecules move?The cell wants to maintain _________________– Molecules are constantly moving in solutions and crossing
membranes
Concentration Gradient – Difference in concentration where molecules move from areas of ______________ concentration to areas of _____________ concentration to maintain a dynamic _______________________.
Dynamic Equilibrium = HomeostasisEven during equilibrium, molecules move back and forth across the membrane but at an equal rate.
• Small molecules pass through the cell membrane directly by squeezing through the phospholipids.
• Larger molecules cannot do this so they must use ________________________
DO NOWDraw arrows and show movement of molecules
**Will the molecules even pass the semipermeable membrane? Why?
Two types of TransportPassive Transport: No energy required
1. Diffusion 2. Facilitated Diffusion3. Osmosis
Active Transport: Uses energy (ATP) for transport 4. Active Transport5. Endocytosis 6. Exocytosis
How do molecules move during passive transport?
1
2
1. DiffusionDiffusion – 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 across cell membrane – small molecules easily diffuse across the phospholipid bilayer (cell membrane)
2. Facilitated Diffusion• Some molecules, such as glucose, are a little too __________to
pass through the membrane by simple diffusion
• These molecules need help and use ______________________ to facilitate their movement
Facilitated diffusion – molecules move from areas of high to low concentration using a carrier or transport protein.
3. Osmosis Osmosis – Diffusion of _________________. Water will move from areas of high to low concentration.
Why is it dangerous to drink salt water?
3. Osmosis Water will always move to where there is more solute (dissolved substances) in water.
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. Where will water come from and go to?
Types of solutions
• Hypertonic – Outside cell contains low water concentration (high dissolved solute concentration). Water moves ___________ of cell.
• Isotonic – Outside of cell contains same water concentration (same solute concentration). Water moves ________________ of cell.
• Hypotonic – Outside of cell contains high water concentration (low solute concentration). Water moves ______________ cell.
Do NowLabel 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)
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
_____________.
• This occurs when molecules are moving from areas of ____________ concentration to areas of __________ concentration.
• Active transport occurs through special transport proteins that push/pull molecules into or out of the cell.
Balloon!
Active Transport Where is the concentration highest?
How would blue diamond get into the cell?
Question…“How would you get this pack of skittles into the bag without exposing the inside of the bag to the outside?”
Materials:• Plastic Bag• Scissors• Two 7” pieces of string • Bag of skittles
Exocytosis Exocytosis – type of active transport where large molecules, such as proteins, or large amounts of material leave or EXIT the cell. Uses ATP
Example – insulin leaves pancreatic cells by exocytosisVacuoles inside cell fuse / connect will cell membrane and empty contents outside the cell.
Exocytosis
Where do the vacuoles go before they leave the cell?
The Golgi Apparatus
EndocytosisEndocytosis – type of active transport where large molecules, such as proteins, or large amounts of material enter the cell. Uses ATP
Phagocytosis = membrane moves out and surrounds big molecule creating a vacuole
Endocytosis
Where does the vacuole go after it is ingested?
Practice Problems
Do NowPredict what will happen in this picture after diffusion occurs. Focus on the amount of molecules / solutes inside and outside the membrane.
I – Iodine G – Glucose S – Starch
Diffusion Lab
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 _________________
Distilled Water
Material Used _________________
Starch
Material Used _________________
Glucose
Blue-Colored Glucose Indicator
Solution
Amber colored Starch Indicator
Solution
What Actually Happened? In Cell? Outside of Cell?
In Cell? Outside of Cell?
Before After
Stuff You Have to KnowWhat 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
Groups (2)1. Your groups are (no changes):
– Group 1 – Madelin, Sam, Melissa, Darlenny, Brian, James J.
– Group 2 – Misael, Braylin, Anthony, Chavonne, Dezmon
– Group 3 – Franlis, Jason, Josh, Oriana, Justin C., Justin L.
– Group 4 –Shakeva, Hannah, Jaylin, Travis, Ceniya, Ariel
– Group 5 – Diego, Elaine, Kristie, Rosa, Alaiyo, Jordan
Groups (2)1. Your groups are (no changes):
– Group 1 – Courtney, Kyrone, Quincy, Alvaro, Rafael
– Group 2 – Anllinette, Ka’Ron, Williams, Alexa, Stephon
– Group 3 – Finch, Tiara, James F, Adalgisa, Jordy
– Group 4 – Richie, Jordan, Luis, Jon R, Justin M.
– Group 5 – Chloe, Melanie, Majesty, Sandy
Groups (2)1. Your groups are (no changes):
– Group 1 – Ramel, Jimmy, Amir, Davin, Zephaniah, Odalys
– Group 2 – Ahdrian, Xavier, Ciara, Antonyo, John M
– Group 3 – Dave, Yanira, Daniel, Tyquan, Gabriel
– Group 4 – Candida, Alex, Matt W, Herrison, Lashae
– Group 5 – Lilliam, Erica, Janaya, Jacques, Anai, Jimmy
What to expect
Onion cells in distilled water
What to expect
Onion cells in distilled water again
DO NOWWrite 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 diffuse across the membrane? 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?
Review…but first
What happened to these cells? What might of caused this?
