1. Human Physiology Unit Three

2. - a covalently bonded, polar molecule
Water
- a covalently bonded, polar molecule
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Molecules are said to be polar if they have slight opposite charges on either end

3. The slight attraction between the negative end of one molecule and the positive end of another results in a…
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4. Water action and surface tension
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- Polarity leads to adhesion and cohesion
Adhesion and cohesion lead to capillary
action and surface tension
High specific heat leads to temperature
stability
High heat of vaporization leads to
evaporative cooling

5. Water Spheres of hydration form electrostatic
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Spheres of hydration form electrostatic
interactions, keeping ions from
interacting with each other
- This characteristic means water has a
high degree of solvency and chemical
reactivity

6. Water Water also ionizes into H+ and OH- which
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Water also ionizes into H+ and OH- which
can be incorporated into other molecules
or released from them

7. Water

8. Fluid Mosaic Model of the
Plasma Membrane

9. Fluid Mosaic Model of the
Plasma Membrane

10. Fluid Mosaic Model of the
Plasma Membrane

11. Fluid Mosaic Model of the
Plasma Membrane

12. Fluid Mosaic Model of the
Plasma Membrane

13. Passive Transport Does not require energy from the cell
Substances move from an area of high concentration to an area of low concentration
Substances can move in both directions, depending on the concentration gradient

14. Examples of Passive Transport
Diffusion – the movement of a substance from an area of high concentration to an area of low concentration
Facilitated diffusion – same as above, but with the help of membrane proteins
Osmosis – the diffusion of water

15. Osmosis Lysed Crenated Aaaaaaaaaaaaa Aaaaaaaaaaaaa Aaaaaaaaaaa

16. Osmosis

17. Osmosis

18. Osmosis
Therefore, the higher the solute concentration, the higher the osmotic pressure
Many body systems create high solute concentrations so as to produce higher osmotic pressure

19. Solute Concentration Measurements
Molarity = one mole of solute/Liter
Osmolarity = one mole of solute particles/Liter
1M C6H12O6 = 1osm (C6H12O6)
1M NaCl = 2osm (Na+ and Cl-)
1M CaCl2 = 3osm (Ca2+ and 2Cl-)

20. Active Transport Does require energy from the cell
Substances move from an area of low concentration to an area of high concentration
Substances can move in only one direction, against the concentration gradient

21. Active Transport Example
Sodium/Potassium pump – a membrane protein that moves sodium out, while moving potassium in

22. Active Transport

23. Membrane Transport

24. Resting Membrane Potential
+ polarization of a cell due to
differences in external & internal
ion concentrations
+ typical RMP is -70mV (more
anions on the inside than
outside)

25. Resting Membrane Potential

26. Resting Membrane Potential

27. Resting Membrane Potential

28. Resting Membrane Potential

29. The Nernst Equation Ex = 61/z log [Xo]/[Xi] Ex = equilibrium potential
z = valence of the ion
[Xo] = [ion] on outside of cell
[Xi] = [ion] on inside of cell

30. Resting Membrane Potential

31. Resting Membrane Potential

32. Action Potentials Action potential: + an electrical (nerve) impulse
+ generated by chemically
mediated channels
+ propagated by charge mediated
channels

33. Action Potentials

34. Action Potentials

35. Action Potentials