All life processes involve chemical reactions –Ex. 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 particleChargeLocation proton +nucleus neutronnonenucleus electron - surrounds nucleus 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-14 –Radioactive 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- >1.7 Polar covalent Covalent- < 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 molecule –Ex. H 2 O, C 6 H 12 O 6

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 body –Synthesis (anabolism) A + BAB –Decomposition (catabolism)AB A + B –Single replacementAB + C AC + B –Double replacement AB + CD AD + CB

Catalyst- effect the rate of reaction without being changed by the reaction –Biological 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 capacity –Requires large amount of heat to change state= heat of vaporization –Serves as lubricant –Protective function (cushioning)

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

Inorganic salts- provide Na+, Cl-, K+, Ca++, Mg++, PO 4 ---, CO 3 --, etc.

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

pH scale measures hydrogen ion concentration –pH 7 = neutral –pH >7= basics (more OH- than H+) –pH <7= acidic (more H+ than OH-) Normal blood pH for humans is 7.35 to 7.45 –If >, alkalosis –If <, acidosis Buffers- maintain pH

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

Monosaccharides- 3 to 7 carbons –Ex. Glucose, fructose, galactose Carbohydrate utilized by the cell Many C 6 H 12 O 6

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

Polysacchride s of monos –Ex. starch

Lipids % in lean adults –Contain C, H, O - neutral –Fats- concentrated energy stored in adipose tissue

Triglycerides –Glycerol + 3 fatty acids Monounsaturated- one double bond Polyunsaturated- 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 % in lean adults –Structural and physiological enzymes –Made of amino acids (20)- held by peptide bonds –3D shape held by H-bonds (denatured with heat) – Fibrous (structural) or globular (functional)

Primary Secondary Tertiary Quaternary

Nucleic acids –Base + sugar + phosphate –DNA and RNA –ATP- provides energy for the cell