A Review Of Chemical And Physical Principles For Human

Physiology

This review is provided as a basic minimum coverage of the physical

and chemical organization of matter in living systems

The Atomic Theory

• All matter consists of tiny particles called atoms

• Atoms are, in turn, made up of three fundamental particles, protons, neutrons, and electrons

THE CARBON ATOM

+

-

PROTONNEUTRON

ELECTRON

ORBITORSHELL

NUCLEUS

ATOMIC STRUCTURE

• PROTONS AND NEUTRONS ARE IN THE NUCLEUS

• ELECTRONS ARE IN ORBITS AROUND THE NUCLEUS

• THERE ARE EQUAL NUMBERS OF PROTONS AND ELECTRONS

THE CARBON ATOM

ORBITORSHELL

NUCLEUS

There are 6 protons, 6 electrons, and 6 neutrons in this atom

ATOMIC MASS

• PROTONS AND NEUTRONS ARE FAR MORE HEAVY THAN ELECTRONS

• THE UNIT OF ATOMIC MASS IS THE MASS OF A PROTON OR NEUTRON

• CARBON HAS AN ATOMIC MASS OF 12, THE TOTAL OF PROTONS PLUS NEUTRONS

ATOMIC NUMBER

• ATOMIC NUMBER OF AN ELEMENT IS THE NUMBER OF PROTONS N THE NUCLEUS

• THE ATOMIC NUMBER IDENTIFIES THE ELEMENT AND DISTIGUISHES IT FROM ALL OTHER ELEMENTS

• THUS CARBON IS THE ELEMENT WITH ATOMIC NUMBER 6

THE CARBON ATOMCARBON HAS ATOMIC NUMBER 6 AND ATOMIC

WEIGHT 12

ORBITORSHELL

NUCLEUS

There are 6 protons, 6 electrons, and 6 neutrons in this atom

CHARACTERISTICS OF SELECTED ELEMENTS

Name Symbol # Protons AtomicNumber

AtomicWeight(amu)

Hydrogen H 1 1 1.01

Carbon C 6 6 12.01

Nitrogen N 7 7 14.01

Oxygen O 8 8 16.00

Sodium Na 11 11 22.99Magnesium Mg 12 12 24.31Phosphorous P 15 15 30.97Sulfur S 16 16 32.06Chlorine Cl 17 17 35.45Potassium K 19 19 39.10Calcium Ca 20 20 40.08

Chemical Bonds and Chemical Compounds

• The shells or orbits which contain the electrons have characteristic occupancy capacity

• The first three are 2, 8, and 8 respectively

• Atoms tend to combine chemically forming either ionic or covalent bonds so that the outer orbits are complete

THE IONIC BOND

Na Cl

SODIUM HAS AN EXCESS ELECTRON, CHLORINE LACKS ONE

THE IONIC BOND

ClNa

ORBITS BECOME COMPLETE BY DONATION OF AN ELECTRON

POSITIVE ION NEGATIVE ION

THE COVALENT BONDORBITS BECOME COMPLETE BY SHARING ELECTRONS

CH

H

H

H

=CH

H

H

H

CHEMICAL REACTIONS

PROCESSES IN WHICH CHEMICAL BONDS ARE FORMED OR BROKEN ARE CALLED CHEMICAL REACTIONS

CH4 + 2O2 CO2 + 2H2O

ENZYMES

• ENZYMES ARE BIOLOGICAL CATALYSTS

• CATALYSTS MAKE REACTIONS GO FASTER

• THEIR NAMES USUALLY END IN “ASE”

• EXAMPLES: ATPASE, KINASE, OXIDASE, ETC.

MOLECULAR WEIGHTS

• THE MOLECULAR WEIGHT IS THE SUM OF THE ATOMIC WEIGHTS OF THE CONSTITUENTS OF THE MOLECULE

• EXAMPLE: WATER (H2O), THE MOLECULAR WEIGHT IS 16 + 1.01 +1.01= 18.02 ATOMIC MASS UNITS

THE MOLE

• THE WEIGHT IN GRAMS EQUIVALENT TO THE ATOMIC OR MOLECULAR WEIGHT IN ATOMIC MASS UNITS

• A MOLE OF WATER HAS A WEIGHT OF 18.02 GRAMS

• A MOLE OF ANY SUBSTANCE CONTAINS AVAGADRO’S NUMBER OF PARTICLES (6.02 x 1023)

SOLUTIONS

• A SOLUTION IS A HOMOGENEOUS MIXTURE

• IT CONTAINS A RELATIVELY LARGE AMMOUNT OF ONE SUBSTANCE, CALLED THE SOLVENT

• IT MAY CONTAIN ANY NUMBER OF SOLUTES IN A FAR LESSER QUANTITY

WATER AS SOLVENT

• WATER IS THE UNIVERSAL BIOLOGICAL SOLVENT

• WATER HAS UNIQUE PROPERTIES UNEQUALED IN NATURE

• WATER IS A POLAR COMPOUND AND IS A GOOD SOLVENT FOR IONS

• WATER DOES NOT MIX WITH NONPOLAR SUBSTANCES SUCH AS OILS

ELECTROLYTE SOLUTIONS

METAL SALTS FORM IONS UPON DISSOLVING IN WATER

NaCl Na+ + Cl-

CaCl2 Ca+ + 2Cl-

MACROMOLECULES

• LARGE MOLECULES CAN BE FORMED WITH COVALENT BONDS BETWEEN SMALLER SUBUNITS

• IN CHEMISTRY THESE ARE CALLED POLYMERS

BIOLOGICAL MOLECULES

• CARBOHYDRATES

• LIPIDS

• PROTEINS

• NUCLEIC ACIDS

• HIGH ENERGY BIOMOLECULES (ATP)

FUNCTIONAL GROUPS

• ORGANIC COMPOUNDS ARE CLASSIFIED IN TERMS OF REACTIVE PARTS OF THE MOLECULES CALLED FUNCTIONAL GROUPS

• ONE IMPORTANT FUNCTIONAL GROUP IS THE ORGANIC ACID

ACIDS, BASES AND SALTS

• CHEMICAL COMPOUNDS CAN BE PROTON DONORS OR ACCEPTORS

• PROTON DONORS ARE ACIDS

• PROTON ACCEPTORS ARE BASES

• ACIDS AND BASES REACT TO NEUTRALIZE EACH OTHER FORMING SALTS

ACID/BASE REACTIONS

HCl + NaOH NaCl + H2O

ACID + BASE SALT + WATER

CARBOHYDRATES

• CONTAIN C, H AND O (nCH2O)

• SIMPLE SUGARS ARE MONOSACCHARIDES (GLUCOSE, GALACTOSE, FRUCTOSE)

• SUGARS FORM POLYMERS: STARCH OR GLYCOGEN (USUALLY A STORAGE FORM)

• SIMPLE SUGARS ARE WATER SOLUABLE

LIPIDS

• FATTY ACIDS

• TRIGLYCERIDES

• PHOSPHOLIPIDS

• STEROIDS

• CHOLESTEROL

PROTEINS

• POLYMERS MADE FROM 20 AMINO ACIDS JOINED IN PEPTIDE BONDS

• MANY IMPORTANT BIOLOGICAL FUNCTIONS INCLUDING ENZYMES

• THE RESULT OF THE GENETIC CODE IN DNA

PROTEIN STRUCTURE

• PRIMARY: THE SEQUENCE OF AMINO ACIDS CODED IN DNA

• SECONDARY: FOLDING INTO HELICAL OR SHEET STRUCTURES DUE TO HYDROGEN BONDING AND OTHER FACTORS

• TERTIARY: SIDE CHAINS INTERACT

• QUATENARY: AGGREGATES FORM

NUCLEIC ACIDS

• DNA: A DOUBLE HELIX FORMED BY TWO POLYMERS OF NUCLEIC ACIDS

• RNA: A SINGLE POLYMER OF NUCLEIC ACID

• COMPLEMENTARY PAIRS OF NUCLEIC ACIDS ENABLE MOLECULES TO DUPLICATE OR COPY EACH OTHER, THE BASIS FOR THE GENETIC CODE

ENERGY CURRENCY

ATP, ADENOSINE TRIPHOSPHATE, IS A HIGH ENERGY COMPOUND WHICH STORES AND TRANSFERS ENERGY

A-P-P - P A-P-P + P + ENERGY