1. Ch. 2: Chemical Levels of Organization
Anatomy & Physiology
Bases on 9th ed. Fundamentals of Anatomy and physiology by Martini/Nath/Bartholomew
Ch. 2: Chemical Levels of Organization

2. Atomic Structure Chemistry – study of matter
Matter – anything with mass and volume
Smallest, stable pieces of matter - atoms

3. Atomic Structure
Protons = positive charge, mass 1 Dalton, found in nucleus
designated by atomic number
unique to each element
Neutrons = neutral/no charge, mass 1 Dalton, found in nucleus
Mass number – protons = neutrons
can vary within same element - Isoptope
Electrons = negative charge, very small mass, found in orbitals
in elemental form # protons = # neutrons
electrons can be gained/lost or shared
reactivity (bonding) of elements depends on electrons

4. Elements Element – substance composed of only one type of atom
Human body contains: 13 elements make up majority and 14 other elements in trace amounts.
CHNOPS
C HOPKINS CaFe Mg NaCl
“ Charlie Hopin’s café, mighty good with salt”
Si, F, Cu, Mn, Zn, Se, Co, Mo, Cd, Cr, Sn, Al, B and V
Vitamin ads , “from A to zinc”

5. Isotopes Atomic weight = average mass of the atoms of an element
This is decimal because of isotopes
Measured in amu (atomic mass units) or Daltons
Mass number = atomic mass rounded to whole number; # protons + # neutrons = Mass number
Mass number - # protons = # neutrons
Isotopes = varying forms of the same element with different numbers of neutrons.
Carbon12 and Carbon 14
Some are radioactive
Some are valuable in medical research

6. Levels of Organization
Chemical ( molecule) – even at this level form determines function… electrons, bond type and bond angle, 3D shapes of molecules like enzymes
Cellular – phosphate and lipids give properties to things like CM and phospholipid bilayer
Tissue – collection of cells working to perform one function
Organ – two or more tissues working in combination
System * know 11 systems with organs and functions
Organism

7. Electrons and Energy Levels
Electrons are found in electron clouds than contain electron shells or orbitals
1st level holds 2 electrons
Other levels hold 8. (yes there are d and f orbitals that hold more – but they over lap with other s and p orbitals, so outer most is never more than 8)
Valence electrons are those in the outermost shell – these determine element reactivity by forming bonds

8. Bonds
Ionic bonds – formed when there is a large difference in electronegativity between atoms. Electron(s) leave one atom and move to another atom
Atom loosing electrons becomes positive
Atoms gaining electrons becomes negative
Covalent bonds – bonds are formed because atoms are overlapping and share electrons
Non polar covalent – shared evenly ( lipids and carbohydrates)
Polar covalent – uneven sharing of electrons creates region of charge known as poles
Hydrogen bonds – form between molecules because regions or edges of molecules have slight charges (important in water and proteins)
Van derWaal interactions – regions of slight charge because electrons are in constant motion and vary around double bonds

9. Calculations
Molecular weight = sum of atomic weights for atoms within a molecule
Water ; H2O (2 H x 1.001) + (1 O x ) = 18
Mole – 6.02 x molecules in the gram atomic weight of a molecule
Molarity – number of moles in a liter of solution

10. Energy Energy is the ability to do work
Kinetic energy – energy of motion; transferred
Potential energy – stored energy; bonds
Lots of work done in body/ cells;
Transport across cell membranes
Move ions across membrane
Contract muscle fibers
Build organic compounds (anabolism)
Decompose organic compounds (catabolism)
ATP is the currency cells – energy is in the P~P bonds

11. Solutions Solution = one substance dissolved in another
Solvent = does the dissolving (liquid or larger amount)
Solute = is dissolved (solid or smaller amount)
Aqueous solution – solution where the solvent is water
common in body/ cells
electrolytes – ions in solution that are able to conduct
electricity. Required for all systems and body functions.

12. Organic Macromolecules
Carbohydrates
Sugars, starches – mostly fuel, some stored, some structural
Lipids
“fats” , oils, waxes – storage of fuel and cushion/ insulation
Proteins
EVERYTHING – CM, fibers, enzymes, hormones, etc
Nucleic Acids
DNA and RNA