AP Bio Exam Review: Unit 1: Biochemistry

Chp 2: Elements of Life 25 elements Hint: Remember CHNOPS 96% : C, O, H, N ~ 4% : P, S, Ca, K & trace elements (ex: Fe, I) Hint: Remember CHNOPS

II. Atomic Structure Charges Atom = smallest unit of matter that retains properties of an element Subatomic particles: Charges Location neutron neutral nucleus proton positive electron negative shell

Bonds Covalent Ionic Hydrogen All important to life Form cell’s molecules Quick reactions H bonds to other electronegative atoms Strong bond Weaker bond (esp. in H2O) Even weaker Made and broken by chemical reactions

Chp 3: Polarity of H2O O- will bond with H+ on a different molecule of H2O = hydrogen bond H2O can form up to 4 bonds

Examples of Benefits to Life H2O Property Chemical Explanation Examples of Benefits to Life Cohesion polar H-bond Water-Water ↑gravity plants, trees transpiration Adhesion Water-Other plants xylem bloodveins Surface Tension diff. in stretch break surface bugswater Specific Heat Absorbs & retains Energy oceanmoderates temps protect marine life (under ice) Evaporation liquidgas KE Cooling Homeostasis Universal Substance Polarityionic Good dissolver solvent

Solvent of life Hydrophilic Hydrophobic Affinity for H2O Appears to repel Polar, ions Nonpolar Cellulose, sugar, salt Oils, lipids Blood Cell membrane

Acids and Bases Acid: adds H+ (protons); pH<7 Bases: adds OH-; pH>7 Buffers = substances which minimize changes in concentration of H+ and OH- in a solution (weak acids and bases) Buffers keep blood at pH ~7.4 pH 5 = 10-5 = .00001 M 10X more acidic or basic

Figure 3.9 The pH of some aqueous solutions

Chp 4: Functional Groups – Organic Chemistry

Names & Characteristics Functional Groups Functional Group Molecular Formula Names & Characteristics Draw an Example Hydroxyl -OH Alcohols Ethanol Carbonyl >CO Ketones (inside skeleton) Aldehydes (at end) Acetone Propanol Carboxyl -COOH Carboxylic acids (organic acids) Acetic acid Amino -NH2 Amines Glycine Sulfhydryl -SH Thiols Ethanethiol Phosphate -OPO32- / -OPO3H2 Organic phosphates Glycerol phosphate

ie. amino acid  peptide  polypeptide  protein Monomers Polymers Macromolecules Small organic Used for building blocks of polymers Connects with condensation reaction (dehydration synthesis) Long molecules of monomers With many identical or similar blocks linked by covalent bonds Giant molecules 2 or more polymers bonded together ie. amino acid  peptide  polypeptide  protein larger smaller

Dehydration Synthesis (Condensation Reaction) Hydrolysis Make polymers Breakdown polymers Monomers  Polymers Polymers  Monomers A + B  AB AB  A + B + H2O + + H2O + Remove water Adding water

Chp 5: Macromolecules

Differ in position & orientation of glycosidic linkage I. Carbohydrates Fuel and building Sugars are the smallest carbs Provide fuel and carbon monosaccharide  disaccharide  polysaccharide Monosaccharides: simple sugars (ie. glucose) Polysaccharides: Storage (plants-starch, animals-glycogen) Structure (plant-cellulose, arthropod-chitin) Differ in position & orientation of glycosidic linkage

II. Lipids Fats: store large amounts of energy saturated, unsaturated, polyunsaturated Steroids: cholesterol and hormones Phospholipids: cell membrane hydrophilic head, hydrophobic tail creates bilayer between cell and external environment Hydrophilic head Hydrophobic tail

Four Levels of Protein Structure: Primary Amino acid sequence 20 different amino acids peptide bonds Secondary Gains 3-D shape (folds, coils) by H-bonding α helix, β pleated sheet Tertiary Bonding between side chains (R groups) of amino acids H & ionic bonds, disulfide bridges Quaternary 2+ polypeptides bond together

amino acids  polypeptides  protein

Protein structure and function are sensitive to chemical and physical conditions Unfolds or denatures if pH, and temperature are not optimal. Others?

Nucleic Acids = Information Monomer: nucleotide IV. Nucleic Acids Nucleic Acids = Information Monomer: nucleotide DNA RNA Double helix Thymine Carries genetic code Longer/larger Sugar = deoxyribose Single strand Uracil Messenger (copies), translator tRNA, rRNA, mRNA, RNAi Work to make protein Sugar = ribose

The End