1. Inorganic Compounds Chemical Bonds Solutions and pH
Cell Chemistry (I)
Inorganic Compounds
Chemical Bonds
Solutions and pH

2. Introduction
Approach this ppt NOT as lecture notes but as an outline of the basic chemistry that you need to know to understand physiology and ease your way into biochemistry.
Most of the information can be found in Ch. 1, 2 or 3 of any college Anat. & Physiol. or college Biology textbook.
This ppt is NOT a substitute for reading the book.

3. Chemical Bonds Review the basic facts about:
Ionic bond
Covalent bond
Polar covalent bond
Hydrogen bond
The next slides illustrates some of these bonds

4. Some Bonds Illustrated (Marieb, Fig. 2.9)

5. Hydrogen Bonds Between Water Molecules (Becker Fig. 2.8)

6. Solubilization of NaCl (Becker Fig. 2.10)

7. Water: Significance in Physiology
Water is essential for life
It is a universal solvent in biological systems because of its:
Polarity, its cohesiveness, its temperature-stabilizing capacity and its solvent properties
Water molecules are held by Hydrogen bonds and these bonds account for its high surface tension, its high boiling point, high specific heat and high heat of vaporization
Cells are about 75-85% water by weight and one’s body weight is about 60% water.

8. Terms Linking Solubility of Solutes in Water
The terms hydrophilic, hydrophobic, amphipathic and oil/water partition coefficient are often used to describe the solubility of a solute in water.
Hydrophilic solutes are usually polar (they have polar covalent bonds or ionic bonds) and because of their polarity dissolve readily in water
Hydrophobic solutes are non-polar, therefore, not soluble in water. They are soluble in organic solvents like benzene. They are rich in non-polar covalent bonds.
Amphipathic solutes have a region that is hydrophilic and another one that is hydrophobic.

9. Surface Tension Allows Insect to Walk on Water

10. Solutions Know examples of acids, bases & salts
Know how to calculate, molarity, osmolarity and equivalentsK
Solutions

11. Solutions Two components: In physiology and in all biological systems:
Solvent
Solute(s)
In physiology and in all biological systems:
the solvent is H2O
The solutes are many (hundreds) like
Nutrients like amino acids, glucose
Electrolytes (in physiology = anions & cations)
Gases like O2 and CO2
Wastes like urea, creatinine, uric acid
Examples of solutions in the body
Plasma
Interstitial fluid
Synovial fluid
Urine

12. Concentration of Solution
Concentration is a ratio of the amount of solute(s) in a given volume of solvent
Amounts are often expressed in
Grams (g)
Milligrams (mg)
Mole (m) or millimole (mM)
Milliequivalent (mEq)
Osmole (Osm) or milliosmole (mOsm)
Volume is often expressed in
Liters (L)
Deciliter(100 mL)
Milliliters (mL)
Microliters
Examples:
0.9% NaCl or 135mmole/L NaCl or 135 mEq /L
GOAL: Given weight in grams, know how to calculate concentrations in molarity, osmolarity and equivalent

13. Units for Concentration of Solutions
Percent (%):
0.9% Sodium chloride (normal saline)
153 mmole/L Sodium chloride (normal saline)
?? Do these have the same amount of NaCl? Justify your answer
Other units commonly used in physiology
mg/dL creatinine
mg/dL glucose
mOsm/Kg H2O (For what?
mEq/L Sodium
Units for amount of gas
mmHg
Volume %
Why should I care about these units?
You will constantly run into them in physiology, in reading patients charts and in reading cases.

14. Inorganic Compounds Characteristic of ionic bonds
Most of the chemical in your body and the foods that you consume are compounds that are classified as:
Inorganic or
Organic
Inorganic compounds
Small
Lack carbon atom (some exceptions? )
Most are composed of minerals like K, Ca, P, Mg, Fe
Their atoms are held by ionic bonds
Characteristic of ionic bonds
They are weak ( easily broken, no enzyme required)

15. Common Examples of Inorganic Compounds Significant in Physiology
Sodium chloride:
NaCl
Calcium phosphate
(Ca)3(PO4)2
Potassium iodide KI
Sodium bicarbonate
Na(HCO3)
Hydrochloric acid
HCl
Sodium hydroxide
NaOH
Magnesium hydroxide
Mg(OH)2
Calcium chloride
CaCl2

16. Sources of Electrolytes in Physiology
In physiology, anions and cations are collectively called electrolytes
Salts
NaCl, KI, Na(HCO3)
Acids (organic and inorganic)
HCl, H2CO3
Lactic acid and Acetoacetic acid
Bases
HCO3-
OH-

17. Ionization of Salts, Acids and Bases
In H2O the ionic bonds in acids, salts and bases break and the atoms dissociate into ions (or ionize).
Examples
Replace question marks with correct answer/s
NaCl -> Na+ + Cl-
KI -> ??
H2CO3 --> H+ + HCO3-
Mg(OH)2  ??

18. What to Do!
Look up/review significance of listed ions in physiology or cell biology.
Example: I- (iodide) is essential for thyroxine (T4) synthesis by the thyroid gland. T4 regulates basal metabolic rate. Now do the same for: H+ K+
Na+
Cl-
Fe++
Ca++

19. Questions? Which one is OR which ones are: HCl H2CO3
A) acid(s)
B) base(s)
C) salt(s)
D) electrolytes
HCl
H2CO3
KI (potassium iodide)
Na(HCO3)
Ca3(PO4)2
NaCl
Na(OH)
Mg(OH)2

20. Inorganic Acids, Bases and Salts
Acids, bases and salts in the diet are major sources electrolytes (anions and cations) in body fluids.
In H2O acids, bases and salts ionize or dissociate into anions and cations.
Examples:
Na:Cl -> Na Cl-
H:Cl -> H+ + Cl-
Na:OH -> Na+ + (OH)-
All ions are not NAKED. They are surrounded by a “shell” of H2O (a hydration shell)
Hydration shell Illustrated on next slide.

21. Solubilization of NaCl (Becker Fig. 2.10)

22. ACIDS, BASES AND PH

23. Acid: Definition & Examples
Substances () that ionize (dissociate) into one or more Hydrogen ion (H+) PLUS one or more anion(s)
H+ is also called a proton.
Acids are also defined as a proton donors or substances that add proton(s) to a solution.
Examples of:
Inorganic acids; ---??
Organic acids: ---??

24. Significance of H+ in Solutions
H+ concentration in a solution affects the acidity or alkalinity of the solution:
pH =log 1/[H+] = -log [H+]
Note log scale and inverse relationship between [H+] and acidity/alkalinity of a solution
? Fill-in blank spaces with the correct term
The higher the [H+] the more ---? the solution
The lower the [H+] the more ---? The solution

25. pH: Note Log Scale Know pH of Some Foods Household Goods

26. Base: Definition and Examples
Substance (electrolyte) that ionizes (dissociates) into one or more hydroxide (OH-) ion(s) PLUS one or more cation(s).
Also defined as substances that accept or bind to or remove free proton(s) from solutions.
HCO3- (What ion is this?) is a major base in body fluids.

27. Salt: Definition and Examples
Substance (electrolyte) dissociate into cations (??) and anions (??) neither of which (??) is H+ or (OH)-
Examples of salts?
Products of reaction between an acid and a base
Example ofsuch a reaction
Na(OH) + HCl -- NaCl + H2O

28. Body Fluid pH Normal body fluid pH is between 7.35 to 7.45.
pH below 7.35 is a condition called acidosis
pH above 7.45 is a condition called alkalosis
Two organs collaborate to maintain normal body fluid pH:
The lungs and the kidneys
The lungs do so by regulating the excretion rate of CO2 and the kidneys, by regulating the excretion rate of HCO3- ions.

29. Questions
Gastric juice (produced by the stomach) has a pH of 5.0 and plasma pH is 7.0.
A) Which one has the lowest H+ concentration: Plasma or gastric juice?
B) The difference in concentration is how many times lower?
Mr. John Doe has a kidney disease that impairs excretion of HCO3-.
A) Would his plasma HCO3- Concentration increase, decrease or remain within the normal range?
B) Is he likely to end up with acidosis, alkalosis or neither? Justify your answer.
Would you expect hyperventilation or hypoventilation to impact your body fluid pH? Justify your answer

30. CHEMISTRY I
The end