1. MOVEMENT THROUGH THE MEMBRANE
CELLULAR MEMBRANE
MOVEMENT THROUGH THE MEMBRANE

2. The Cell Theory Anton Von Leeuwenkoek Robert Hooke
Developed the first microscope
Robert Hooke
Named the “cell”
The Cell Theory states that all organisms are made up of basic living units called the cells

3. EUKARYOTE v PROKARYOTE
A eukaryote is any organism whose cells contain a nucleus and other structures (organelles) enclosed within membranes.
The prokaryotes are a group of organisms whose cells lack a membrane-bound nucleus (karyon).

4. Cells Are Classified by Internal Organization
Eukaryotes have:
Plasma membrane
Nucleus: information center
Cytoplasm: fluid within membrane
Organelles: structures with specialized functions
Prokaryotes
No nucleus
No true organelles

5. Cell Structure Reflects Cell Function
Muscle cells: contain numerous organelles providing energy needed for muscle contraction
Nerve cells: are long and thin to carry impulses over distance
Small size is efficient

6. The Cell

7. Body Fluid Compartments
EC fluid
IC fluid
Exchange
much more
selective;
Why ?
Interstitial fluid
plasma
Relatively free exchange

8. The Cell Membrane Fluid Mosaic Model Phospholipids Integral Proteins
Peripheral Proteins
Glycocalyx
Glycoproteins
MHC
Glycolipids
Cholesterol

9. Cell Membrane Structure: Fluid Mosaic Model
Thickness ~ 8nm
Cell Membrane Structure: Fluid Mosaic Model
PLs
Cholesterol
Proteins: peripheral (associated) or integral

12. Passive Transport Active Transport Diffusion Always protein-mediated
Simple diffusion
Facilitated diffusion
Osmosis
Active Transport
Always protein-mediated
Primary
Secondary
Endocytosis
Exocytosis

14. Diffusion: Passive Transport Through Membrane
Passive transport: no energy required
Diffusion: movement from area of high concentration to low
Diffusion: Passive Transport Through Membrane

15. Three Forms of Passive Transport
Passive transport is powered by the concentration gradient. In the cell it occurs as:
Diffusion through lipid layer
Diffusion through protein channels
Facilitated transport: transport or carrier proteins in membrane assist in moving molecules across the membrane, down the concentration gradient, without expending energy

21. http://highered. mcgraw-hill

22. Osmosis: net diffusion of water
across a semipermeable membrane

24. Red Blood Cells in Isotonic and Hypotonic Solutions24

25. Variations in Tonicity
Isotonic: extracellular and intracellular ionic concentration equal
Hypotonic: extracellular ionic concentration less than intracellular
Hypertonic: extracellular ionic concentration more than intracellular

26. Active transport requires energy to move substances from an area of lower concentration to an area of higher concentration.
Active Transport

29. 2° ACTIVE TRANSPORT Symport Antiport
Molecules are carried in same direction
Examples: Glucose and Na+
Antiport
Molecules are carried in opposite direction
Examples: Na+/K+ pump

30. Vesicular Transport Movement of macromolecules across cell membrane:
Phagocytosis (specialized cells only)
Macrophage or Phagocytes
2. Pinocytosis
“Cell drinking”
3. Receptor mediated endocytosis
Down Regulation
4. Exocytosis

31. Endocytosis and Exocytosis Move Materials in Bulk
Endocytosis moves material into cell
Exocytosis moves material out of cell

36. the end