Types of Chemical Reactions Synthesis Decomposition Exchange Reversible

Synthesis Atoms or small molecules combine to form large molecules, absorb energy Anabolism - all synthesis reactions of the body A + B  AB Dehydration synthesis - anabolism that releases a water molecule

Decomposition Larger molecules broken into smaller parts, energy released Catabolism - all decomp reactions of the body AB  A + B Hydrolysis - catabolism using water to break molecules

Exchange Decomposition, then synthesis AB + CD  AC + BD

Reversible A reaction that can go in either direction AB  A + B Most of the body’s reversible reactions require enzymes

Types of Molecules Inorganic Organic

inorganic Usually no carbon, not part of the structure of living things Acids, bases, salts, water Acids and bases –Measured on a pH scale, acids from , neutral is 7, and bases from Salts -dissolves into ions –Used by muscles and nerves + in cell metabolism –As electrolytes, ions carry electrical currents

inorganic, con’t Water - makes up 60-70% of cells –Medium for almost all body reactions –Has a polar nature As a solvent: - dissolves a solute  becomes a solution -provides ions -Allows metabolism -Dissolves waste so it can be removed Water cannot dissolve lipids

inorganic, water, con’t As a lubricant –Internal organs, muscle and bone, move together without abrasion With a high heat capacity –Can maintain body temp because it holds its own temp so well In chemical reactions –hydrolysis or dehydration synthesis

organic Contains carbon Makes up the structures of living things Carbohydrates, lipids, proteins, nucleic acids, ATP Carbohydrates -hydrates of Carbon: C(H 2 O) Size: Small, single chains/rings or 1000s of rings Ex: sugars, starch, glycogen, cellulose Functions: food energy(glucose) for cells to convert to ATP - 4cal./g and part of structure

organic Lipids - C, H, O - usually don’t dissolve in water Ex: waxes, fats, oils some vitamins: A, D, E, K pigments hormones : steroids, cholesterol, bile salts, Vit D, sex hormones Lipid functions: *stored energy, 9cal./g *structure -cell membrane *protection -around organs

organic lipids, con’t Fats = glycerol + fatty acids (ester linkage) Unsaturated from plants »L»Liquid at room temp »h»healthier Saturated from animals »S»Solid at room temp »U»Usually unhealthy

organic, proteins Proteins - C, H, O, N (+S, P, Mg) Amino  polypeptide  Protein acids chains 4 levels: primary - quaternary Leads to unique shapes Shape dependent - must maintain shape to perform function Denaturation - loss of shape, caused by temp change, pH change

organic, protein functions 1.Structural - collagen 2.Regulatory - hormones like insulin 3.Contractile - muscles 4.Immunological - antibodies 5.Transport - hemoglobin of red blood cells, heme has Fe to hold O 2 6.Catalytic - enzymes as catalysts control direction and rate of reactions

organic, nucleic acids C, H, O, N, P The base unit of a nucleic acid is a nucleotide. A nucleotide is made of a: phosphate group + sugar + N base Functions: hold and activate genetic info Be a “blueprint” for every cellular activity + structure Ex: DNA & RNA

organic, nucleic acids, con’t DNA 2 strands, double helix Stays in nucleus Holds “blueprints for life” RNA Single strand Moves from nucleus to ribosomes Carries “blueprint” to “construction site”

organic, ATP ATP C, H, O, N, P 3 phosphate groups + sugar + N base Function: provide metered doses of energy for every cellular function Cellular energy - the only type cells can use Energy acquired from glucose (food energy) within the bonds that hold phosphate groups together 1 glucose  36 ATP