Download - 7 3 cell boundaries
Unit 3: Cells
Chapter 7: Cell Structure & Function
7-3: Cell Boundaries
Ms. PetrucciBiology
Cell Boundaries
Cell Wall
• Provides support and protection for the cell.
• Made from carbohydrate and protein fibers.
• Found in plants, algae, fungi and many prokaryotes.
• Cellulose
Plasma Membrane
• AKA Plasma membrane
• Protective barrier between the cytoplasm and the outside environment that provides support to the cell.
• Controls everything that goes into and out of the cell.
• Selectively permeable/ semipermeable
Phospholipid Structure• Composed of
phospholipids (fatty acids and alcohols)
• Phospholipids contain a phosphate group
• Bilayer – arranged in 2 layers
Other Molecules in the Membrane
• Proteins (integral and peripheral)– Channels
– Pumps
• Lipids– Cholesterol (animal cell
membranes only)
• Carbohydrates– Attached to proteins– Chemical identification
cards
Types of Membrane Proteins
http://education-portal.com/academy/lesson/membrane-proteins-functions-types tructure.html#lesson
Diffusion Through Cell Boundaries
• Movement of molecules from one side of the membrane to the other is an important functions of the cell membrane.
• Recall from Chapter 2:– What is a solution?– What is a Solute?– What is a Solvent?
• The CONCENTRATION of a solution is the mass of solute in a given volume of solution.
Lets look at Concentration
Diffusion
• What is diffusion?
Simple Diffusion
Facilitated Diffusion
Osmosis
http://lh5.ggpht.com/-NszBjuqRNSM/Uor7263L-RI/AAAAAAAAAZ0/CBsGMDs5FHE/s1600/osmosis%25255B4%25255D.gif
The movement of water molecules
through a semipermeable membrane rom
the region of higher water
concentration to the region of lesser water
concentration
Osmosis
https://www.youtube.com/watch?v=w3_8FSrqc-I
Osmotic Pressure
Osmotic Pressure
https://www.youtube.com/watch?v=yguSfhiTIfY
Active Transport
ATP
Sodium-Potassium Pump
Vesicle Transport
Endocytosis in Animal Cells
Exocytosis
Homeostasis and Cell Function