P p info on p h #3
- 2. H20 H+ + OH- Living organisms are composed mainly of H2O. Some water molecules tend to separate into ions, forming solutions that are acidic or alkaline. Therefore, in order to understand biochemical processes, we need to know a little about acids and bases
- 3. Ionization of Water H2O H+ + OH- Covalent dissociates Bonding (splits) Ionization of Water Same # of H+ as OH - = a neutral solution
- 4. Acids Acid = Have more H+ ions in solution. Examples HCl H+ + Cl- H2SO4 2 H++ SO4-
- 5. BASES Bases have more OH- in solution Examples: NaOH Na+ + OH- Al(OH)3 Al3+ + OH-
- 6. A pH scale (color coded)
- 7. What do the pH #’s mean?
- 8. pH = a measure of H+ concentrations
- 9. HUMAN pH Our bodies have a pH of 7.4 Stomach pH =1 to 2 Acceptable range is 6.5- 7.5, otherwise its lethal (coma or death)
- 10. HOMEOSTASIS A mechanism to maintain body’s stabilization, Human pH range is between 6.5 -7.5 One way to keep the body stable is through pH and buffers. H+ + HCO32- H2CO3 H2O + CO2 carbonic acid
- 11. BUFFER Buffers are weak acids & bases that rxt with strong acid & bases in the body to maintain homeostasis. A buffer is a substance which accepts H+ ions or gives off H+ in order to maintain the pH of a system
- 12. New Stuff =Water Polarity
- 13. Polarity H2O is a polar molecule because of the unequal distribution of e- between hydrogen and oxygen. Neg. pole near oxygen atom & positive pole is between the hydrogens
- 14. Cohesion The attraction between molecules of the same substance Explains why H2O beads up Explains why some insects & spiders can walk on water
- 15. Adhesion Attraction between molecules of different substances
- 16. Capillary Action Due to adhesion between H2O & glass, the water can rise in a narrow tube against the force of gravity.