Download Effect of pH on Cells 2014

Homeostasis:
The Effect of pH on Cells
Organisms need certain
conditions to live
Correct temperature
Correct hydration (water)
Correct amount of light
Correct pH
pH
pH means potential hydrogen
pH measures of the H+ concentration of a solution.
pH tells how strong an acid or base is
Living things need...
A neutral pH
(pH = 7)
If acidic or basic they will die
How can living things
maintain a neutral pH?
Let’s look back at acids and bases
Acids
ionic compounds (+ or - charge) that break apart in
water and release hydrogen ion (H+) [positive ion]
Stronger acids have MORE H+ (a higher
concentration of H+)
pH of an acid is from 0-6 on the pH scale
Example: hydrochloric acid (HCl)
(We will use this in the lab)
Bases
ionic compounds that break apart in water to form a
negatively charged hydroxide ion (OH-)
pH of a base is from 8-14 on the pH scale
Stronger bases have MORE OH- (a higher
concentration of OH-)
Example: Sodium hydroxide (NaOH)
(We will use this in the lab today)
Back to Living
Things/Cells...
How do living things maintain their pH? (aka:
maintain homeostasis)
Buffers
Buffers
maintain a concentration of H+ within the
physiological range (blood/cells pH 7.35-7.45)
Help control reaction rates in cells
Help maintain the proper pH
The Liver
Detoxifies blood (drugs and alcohol)
Produces bile (digestion)
Plays a major role in metabolism
We will be using liver in the next lab (organ made of
cells)