Chapter 2: Chemical Level of Organization General Chemistry Atoms:elements Molecules:compounds Chemical reactions Biological Chemistry (Inorganic) Biological Chemistry (Organic)
Matter and Energy Matter Occupies space Has mass (weight?) 3 states of matter Solid Liquid Gas Energy =capacity to do work 2 forms Potential Chemical energy-stored in bonds of compounds/ molecules Kinetic-energy in motion! Law of Conservation of Energy Not created or destroyed, but only converted
Definitions Atom-the smallest unit of matter that retains the properties and characteristics of the element Atomic number= # protons in the nucleus Mass number= sum of protons and neutrons Isotope= atoms of an element w/different numbers of neutrons
Structure of the Atom Subatomic particles: Proton Neutron Electron valence shell (2,8,18,18)
Atomic Structure: Periodic Table
Molecules/Compounds Molecule 2 or more atoms that share electrons (O2) Compound 2 or more atoms from different elements (H2O, NaCl)
Chemical Bonds: Ionic Ionic bond= force of attraction that holds together ions with opposite charges Cation (+) Anion (-) Ionic compounds as solids/ crystals (in body-teeth and bones) Electrolytes in solution (NaCl)
Chemical Bonds: Covalent 2 or more atoms share electrons Most common bond in body More electrons shared: stronger bond Single covalent bond (H) Double covalent bond (O) Triple covalent bond (N) Polar /nonpolar
Hydrogen Bonds Form from attraction of oppositely charges parts of molecules Weak-cannot bind atoms into molecules Link different parts of large molecules Cohesion of water molecules create surface tension
Chemical Reactions Occur when new bonds form or old bonds break between atoms Reactants Products Metabolism-all chemical rxns occurring in body
Chemical Reactions: Energy Transfer Potential: position Kinetic: matter in motion Chemical: stored in bonds of compounds and molecules Activation energy Concentration Temperature (Law of Conservation of Energy) Exergonic Endergonic
Energy Transfer (cont d): Catalysts Chemical compounds that speed up rxns by lowering activation energy needed Does not change difference in potential energy enzymes
Chemical Reactions: Types Synthesis reactions (anabolic) New and larger molecules (A + B AB) Anabolic rxns usually endergonic Decomposition reactions (catabolic) Large molecules smaller atoms, ions or molecules (AB A + B) Catabolic rxns usually exergonic
Chemical Reactions: Types Exchange reactions Consist of both synthesis and decomposition (AB + CD -> AD + BC) (Ex: HCl + NaHCO3 -> H2CO3 + NaCl) Reversible reactions The products can revert to the original reactants (AB A + B) Irreversible reactions
Solutions/ Colloids /Suspensions Mixture-combo of elements that are physically blended but not bound by chemical bonds A solvent dissolves another substance called a solute into a solution Colloid- a solution where the solute particles are large enough to scatter light Suspension- suspended material eventually settles out
Inorganic Compounds: Water Polarity Excellent solvent Hydrophilic Hydrophobic Cohesion Chemical reactions Hydrolysis (Larger + water -> smaller) Dehydration synthesis (2 smaller -> larger + water) High heat capacity (H bonds) High heat of vaporization Lubricant (pleura, pericardium, joints, GIT)
Inorganic Acids, Bases, and Salts Acid-dissociates into H+ and anion (proton donor) Base-removes H+ from solution (proton acceptormany dissociate into OHand cation) Salt- dissociates into cations and anions, neither H+ or OH-
Acid-Base Balance: ph ph=concentration of H+ (moles/liter) ph 7=.0000001 mole H+ per liter (concentration H + = concentration OH-) ph < 7: acidic solution ph > 7: basic solution
Maintaining ph: Buffer systems Normal blood ph range: 7.35-7.45 Acidosis: ph < 7.35 Alkalosis: ph > 7.45 Buffer systems convert strong acids/bases into weak acids/bases Carbonic acid-bicarbonate buffer system (H+ + HCO3- H2CO3)
Organic Compounds Large, complex, usually covalent bonds Carbon (C )- 4 electrons in valence shell Can form chains called carbon skeletons Can bond to H+ atoms forming hydrocarbons Polymer- macromolecule with repeating monomer Isomer- same molecular formula but different structure Include carbohydrates, lipids, proteins, nucleotides and nucleic acids.
Organic Compounds: Carbohydrates Made up of C, H, O Include sugars, glycogen, starches, cellulose Function mainly as source of chemical energy (ATP) Monosaccharides Disaccharides Polysaccharides
Carbohydrates: Monosaccharides Simple sugars Monomers used to build carbohydrates Prefix = # C atoms Suffix -ose
Carbohydrates: Disaccharides Formed from two monosaccharides by dehydration synthesis Can be split into smaller, simpler molecules by hydrolysis
Carbohydrates: Polysaccharides Contain tens to hundreds of monosaccharides join through dehydration synthesis Insoluble in water, not sweet Includes glycogen, starches, cellulose
Organic Compounds: Lipids Contain C, H, O, but not 2:1 ratio H:O Less O- atoms so fewer covalent bondshydrophobic Lipoproteins are soluble Fatty acids, triglycerides, phospholipids, steroids, vitamins, lipoproteins
Lipids: Fatty Acids Carboxyl group and hydrocarbon chain Saturated: only single covalent bonds Unsaturated: one or more double covalent bonds -monounsaturated -polyunsaturated
Lipids: Triglycerides 3-C glycerol backbone plus 3 fatty acids Ester linkage Most highly concentrated chemical energy Fat- solid at room temperature; mostly saturated (meat/ dairy, cocoa butter, palm oil) Oil- liquid @ room temperature; mostly unsaturated Monounsaturated (olive/peanut/canola oil, avocado) Polyunsaturated (corn/safflower/soy oil, fatty fish)
Lipids: Phospholipids Glycerol backbone and two fatty acids (nonpolar) Charged phosphate head is polar Amphipathic-(polar/ nonpolar parts)
Lipids: Steroids 4 carbon rings Steroids synthesized from cholestrol Sterols- have at least one hydroxyl (alcohol) group; weakly polar Weakly amphipathic
Lipids: Eiconasoids Prostaglandins, Leukotrienes! Modify responses to hormones Contribute to inflammatory response Prevent stomach ulcers Dilate airways Regulate body temperature Influence blood clot formation, etc.
Organic Compounds: Proteins Contain C, H, O, and N (S) Many functions Amino acids: monomer building blocks
Proteins: Amino Acids H atom and 3 functional groups attached to central C: Amino group (- NH3) Acidic carboxyl group (-COOH) - Side chain (R group)
Amino Acids: Peptide Bonds Covalent bonds joining sequential aa s Form b/t C of carboxyl and N of amino groups Dehydration synthesis rxn Dipeptide tripeptide peptide (4-9) polypeptide ( 10-2000+)
Proteins: Structural Levels Primary Sequence of aa s Secondary Repeated twisting/folding Tertiary 3-D shape Quaternary Arrangement of multiple chains Denaturation (unravelling)
Proteins: Enzymes Primary catalysts for biochemical reactions Usually end in -ase 3 properties: Specific (substrates) Efficient (100M-10Bx) Subject to cellular controls (enhance or inhibit)
Organic Compounds: Nucleic Acids First discovered in nuclei (ca. 1953) Contain C, H, O, N, P DNA: inherited genetic material RNA: relays instructions for protein synthesis Chains of repeating nucleotides
Nucleic Acids: Nucleotides Pentose sugar Deoxyribose (DNA) Ribose (RNA) Phosphate groupalternate w/sugars to form backbone Nitrogenous base Purines (A, G) Pyrimidines (T/U, C)
Organic Compounds: Adenosine Triphosphate ATP- Energy currency of living systems (from exergonic catabolic rxns) Cellular respiration (glucose catabolism) ~Anaerobic phase: 2 ATP (glucose -> pyruvic acid) ~Aerobic phase: 36-8 ATP (glucose -> CO2 + H2O) ATPase ATP + H2O ADP + P + E ATP synthase