1. Cell Membrane Outside of cell Inside (cytoplasm) Carbohydrate chains
Proteins
Protein
channel
Lipid bilayer
Carbohydrate
chains

2. TAKS
Objective 2 – The student will demonstrate an understanding of living systems and the environment.

3. TEKS Science Concepts
4 -The student knows that cells are the basic structures of all living things and have specialized parts that perform specific functions, and that viruses are different from cells and have different properties and functions. The student is expected t
(B) investigate and identify cellular processes including homeostasis, permeability, energy production, transportation of molecules, disposal of wastes, function of cellular parts, and synthesis of new molecules

4. Engage

5. Explore Semi-Permeability Lab Eggactly What I Predicted
Cell Membrane Manipulative

6. Membrane structure Semi-Permeable Selectively Permeable
Amphipathic~ hydrophobic & hydrophilic regions
Fluid Mosaic Model

7. The Structure of the Cell Membrane
Outside
of cell
Inside
(cytoplasm)
Cell
membrane
Proteins
Protein
channel
Lipid bilayer
Carbohydrate
chains

8. Membrane structure Phospholipids~ membrane fluidity
Cholesterol~ membrane stabilization and fluidity
“Mosaic” Structure~
Integral proteins~ transmembrane proteins
Peripheral proteins~ surface of membrane proteins
Membrane carbohydrates ~ cell to cell recognition;

9. Video 1

10. Random movement results in
Solution – mixture of solute and solvent
Solute – substance being dissolved
Solvent – substance dissolving solute
Living Things (Universal Solvent)-Water

11. Membrane traffic
Passive transport~ diffusion of a substance across a biological membrane (NO ENERGY)
[] = concentration
Diffusion~ the overall movement of particles from a region of high [] to an area of low []
Osmosis~ the diffusion of water across a selectively permeable membrane

12. Results of Diffusion Dynamic equilibrium Homeostasis
Once diffusion has evenly distributed the solute throughout the solvent; movement of particles continues with no change in []
Homeostasis
Preservation of equilibrium

13. Diffusion depends on [] gradient
[] gradient: the difference in [] of a substance across space
Diffusion is said to move down a [] gradient
Diffusion continues until there is NO [] gradient
Ex: O2 diffuses into oxygen depleted blood

14. Diffusion
Small molecules like WATER, OXYGEN, AND CARBON DIOXIDE can move in and out freely.
Large molecules like PROTEINS AND CARBOHYDRATES CANNOT
Charged IONS CANNOT

15. Osmosis
Video 2

16. Osmosis~ the diffusion of water across a selectively permeable membrane

17. Questions Osmosis is the diffusion of _______ across a cell membrane.
Osmosis and Diffusion are both types of __________ transport.
Passive transport does or does not require energy?
Small molecules can not move across freely. T or F
Large molecules can move freely. T or F

18. Three Different Types of Solutions
Isotonic Solution
Hypotonic Solution
Hypertonic Solution

19. Isotonic Solution
The solute outside the cell is equal in concentration to the solute in the cell.
The cell retains its shape.
water moves equally in both directions

20. Hypotonic Solutions
Solution outside the blood cell contains a lower [] of solute than inside of the cell.
Water will diffuse in.
cell will lyse (burst).
Animal cells - cytolysis.
Plant cells do not burst- turgur pressure— grocers use this idea

21. Cells in a Hypotonic Solution

22. Hypertonic Solutions
The solution outside the cell has a higher [] of solute than inside of the cell.
Water will diffuse out of the cell,
causing the cell to shrink
or crenate
Why should you not salt meat before cooking? CRENATION PLASMOLYSIS

23. Cells in a Hypertonic Solution

24. In what type of solution would these cells be found?

25. Water balance Summary Osmoregulation~ control of water balance
Hypertonic~ higher concentration of solutes
Hypotonic~ lower concentration of solutes
Isotonic~ equal concentrations of solutes

26. Water balance Summary
Osmoregulation~ control in cells with cell walls:
Turgid (very firm) - Hypo
Flaccid (limp) - Iso
Plasmolysis~ Hyper
plasma membrane pulls away from cell wall

27. Plasmolysis Turgidity

28. Other Ways to Transport Molecules Across the Plasma Membrane
Selective Transport

29. Review Covered Passive Transport
Osmosis
Does it require energy?
NO!!!
Diffusion

30. Osmosis What is osmosis? WATER
The movement of ___________ across the cell membrane.
Is it the movement of any other substance?
NO!!!!
WATER

31. Diffusion Mixing of two substances by the random motion of molecules.
Molecules move from a region of high concentration to an area of low concentration.

32. How do other molecules cross the cell membrane???
Selective Transport
Facilitated Diffusion (Another Passive Transport)
Active Transport
Protein Pumps
Endocytosis
Exocytosis

34. Selective Transport There are two types of selective transport
Facilitated Diffusion
DOES NOT require the use of energy
Active Transport
DOES require the use of energy

35. Facilitated Diffusion
Glucose
molecules
High
Concentration
Cell
Membrane
Low
Concentration
Protein
channel

36. Facilitated Diffusion
Does facilitated diffusion require the use of energy?
NO!!!!
It uses a [] gradient to transport molecules
The molecules move from an area of high [] to an area of low []
Most SUGAR molecules pass across the cell membrane by this method of transport

37. Carrier Proteins Carry Molecules Across the Membrane
Good Example - transport of Glucose into the Cell

39. Active Transport Does active transport require the use of energy?
YES!!!
It uses ATP
Transports against the [] gradient.
Low to High []
Sodium Potassium Pump, Endocytosis and Exocytosis

40. Active Transport
Molecule to
be carried
Molecule
being carried
Energy

41. Active Transport: Sodium Potassium Pump
Move Sodium out of the cell
Move Potassium into the cell
Uses energy (ATP)
Causes the protein to change shape
Move against a [] gradient

42. Sodium Potassium Pump

43. Bulk Transport-Active
Endocytosis
Pinocytosis
Phagocytosis
Exocytosis

45. Endocytosis
During ENDOCYTOSIS the Cell Membrane folds into a POUCH (Vescicle) that Encloses the Particles.

46. Two Types of Endocytosis: Pinocytosis and Phagocytosis
PINOCYTOSIS ---"CELL DRINKING“—Small Particles
PHAGOCYTOSIS---- "CELL EATING“-Large Particles

47. Treatments

48. Exocytosis EXOCYTOSIS is the opposite OR reverse of ENDOCYTOSIS.
EXOCYTOSIS, wastes and cell products leave the cell.

50. Specialized Transport Summary
Transport proteins
Facilitated diffusion~ passage of molecules and ions with transport proteins across a membrane down the [] gradient
Active transport~ movement of a substance against its [] gradient with the help of cellular energy

51. Elaborate
Cell Membrane Bubbles
Cellular Transport Flow Chart