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

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

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

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”

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

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

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

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

Calculations Molecular weight = sum of atomic weights for atoms within a molecule Water ; H2O (2 H x 1.001) + (1 O x 15.998) = 18 Mole – 6.02 x 10 23 molecules in the gram atomic weight of a molecule Molarity – number of moles in a liter of solution

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

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.

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