All life processes involve chemical reactionsEx. Ca++ in muscle contraction Na+, K+ in nerve impulses

Matter- anything that has mass and takes up space

Energy- the capacity to do work

There are 92 naturally occurring elements (112 known)Living organisms require about 26 of these elements (table 2.1)About 96% (by mass) comes from Oxygen (O), Carbon (C), Hydrogen (H), and Nitrogen (N)

Atoms- smallest complete unit of an element

Subatomic particleChargeLocationproton +nucleusneutronnonenucleuselectron - surroundsnucleus

Atomic number (#)= number of protons (=number of electrons in neutral atom)Mass number (AM)= number of protons + number of neutrons

Isotopes- atoms of same element, different mass (due to neutrons)Ex. C-12 and C-14Radioactive isotopes used in many medical tests (ex. I-131 for thyroid activity)

Ions- charged particles (form ionic bonds)

Find the Face (in the Beans)

Bonds (ionic and covalent)- lose, gain or share electrons in order to fill valence shell (stability)All atoms want 8 e- in their outermost shell

Due to electronegativity!Ionic- >1.7Polar covalent- 0.4- 1.7Covalent- < 0.4

Hydrogen bonds- attraction of H to partial negative charge (due to polar covalent bonds between oxygen and hydrogen)

Molecular formula- represents the numbers and types of atoms in a moleculeEx. H2O , C6H12O6

Isomer- molecules with the same chemical formula and with the same kinds of bonds between atoms, but in which the atoms are arranged differently. Isomers typically share similar if not identical properties in most chemical contexts.

Metabolism= sum of all chemical reactions in the bodySynthesis (anabolism) A + BABDecomposition (catabolism)AB A + BSingle replacementAB + C AC + BDouble replacement AB + CD AD + CB

Catalyst- effect the rate of reaction without being changed by the reactionBiological catalyst= enzyme (-ase)

Water (60% RBC, 75% muscles, 92% plasma)Participates in chemical reactions (ex. Hydrolysis)Carries chemicals within body (good solvent)Can absorb and transport heat (homeostasis)= heat capacityRequires large amount of heat to change state= heat of vaporizationServes as lubricantProtective function (cushioning)

Oxygen- used to release energy from glucoseCarbon dioxide- waste of metabolic processes

Inorganic salts- provide Na+, Cl-, K+, Ca++, Mg++, PO4---, CO3--, etc.

Electrolytes- substances that release ions in water (will conduct an electrical current)Acids- release H+ ionsBases- release OH- ions

pH scale measures hydrogen ion concentrationpH 7 = neutralpH >7= basics (more OH- than H+)pH , alkalosisIf < , acidosisBuffers- maintain pH

Carbohydrates- sugars, starches, glycogen, cellulose 2-3% body weightPlants- starches and cellulose (cannot digest)Animals- source of energy- stored as glycogen

Monosaccharides- 3 to 7 carbonsEx. Glucose, fructose, galactose Carbohydrateutilized by thecellMany C6H12O6

Disaccharides- 2 monos combine by dehydration synthesis (condensation)Ex. SucroseBroken apart by hydrolysis (add water)

Polysacchride- 10-100s of monosEx. starch

Lipids- 18-25% in lean adultsContain C, H, O - neutralFats- concentrated energy stored in adipose tissue

TriglyceridesGlycerol + 3 fatty acidsMonounsaturated- one double bondPolyunsaturated- more than one double bond

Saturated- no double bonds

Phospholipids- polar head and 2 non-polar tails (membrane)

Steroids- cholesterol, sex hormones, cortisol, etc.

Proteins- 12-18% in lean adultsStructural and physiological enzymesMade of amino acids (20)- held by peptide bonds3D shape held by H-bonds (denatured with heat) Fibrous (structural) or globular (functional)

PrimarySecondaryTertiaryQuaternary

Nucleic acidsBase + sugar + phosphateDNA and RNAATP- provides energy for the cell