1. Cell Membrane Transport

2. GPS Standards
SAP1. Students will analyze anatomical structures in relationship to their physiological functions.
Relate cellular metabolism and transport to homeostasis and cellular reproduction.

3. Learning Goals By the end of this section, you will be able to:
Describe the components of the cell membrane and their functions.
Relate cellular transport to homeostasis.
Differentiate between passive transport processes and active transport processes.

4. Medical Terminology
Use prefixes, suffixes, and roots sheet to define the following:
Use prefixes, suffixes, and roots to define the following:
bi-
endo-
exo-
extra-
hydro-
inter-
intra-
phago-
pino-
trans-
-osis
-philic
-phobic
cyt
integral
peripheral
transport
bilayer
extracellular
endocytosis
exocytosis
hydrophilic
hydrophobic
integral protein
intracellular
peripheral protein
phagocytosis
pinocytosis
prefix suffix root

5. The Cell Membrane
The cell membrane is a selectively permeable membrane that determines which molecules can come into the cell and which molecules can leave the cell.

6. Transverse Section of the cell membrane
Nucleus
Cell Membrane
Transverse Section of the cell membrane

7. The Cell Membrane

8. Cell Membrane Components
Phospholipid bilayer
Made up of
Hydrophilic head
Hydrophobic tail
Allows small molecules, like water and gases, to pass through the membrane easily

9. Cell Membrane Components Continued
Proteins
Integral proteins
Permanently imbedded in the membrane
Used as carrier proteins for large molecules
Peripheral proteins
Loosely bonded to the internal and external surfaces of the membrane
Mainly used in cell to cell communication and the immune response

10. Passive Transport
A process that moves molecules across the cell membrane without energy from the cell
Moves molecules from high to low concentrations
Like riding a bike downhill
Processes
Diffusion
Osmosis
Facilitated Diffusion

11. Diffusion
The movement of molecules from an area of higher concentration to an area of lower concentration.

12. Diffusion

13. Osmosis
The diffusion of water across a selectively permeable membrane.
Osmotic solutions can be
Hypotonic (hypo- means “less than”)
Isotonic (iso- means “the same”)
Hypertonic (hyper- means “more than”)

14. Osmosis
Hypertonic
Isotonic
Hypotonic

15. Cells in Osmotic Solutions

16. Facilitated Diffusion
The diffusion of molecules across a membrane with the help of transport molecules imbedded in the cell membrane.

17. Facilitated Diffusion

18. Facilitated Diffusion

19. Active Transport
A process that drives large molecules across the cell membrane from a region of lower concentration to a region of higher concentration
Like riding a bike uphill
Processes
Endocytosis
Exocytosis
Ion Pumps

20. Endocytosis
Molecules are brought into the cell by vesicles formed from the cell membrane
Processes
Pinocytosis. The cell takes tiny droplets from its surroundings into tiny vesicles.
Phagocytosis. The vesicle engulfs food particles that are digested by lysosomes.

21. Endocytosis

23. Exocytosis
Molecules are forced out of the cell by vesicles made by the Golgi apparatus

24. Exocytosis

25. Exocytosis

26. Ion Pumps
Ion pumps use integral proteins and energy (ATP) to transport ions, such as sodium (Na) and potassium (K) across the membrane.