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Chemistry. Biological Molecules. Ch 2b. Introduction to important molecules which comprise the structure and function of all living organisms. Biological Compounds. Categories:. Carbohydrates. Lipids. Proteins. Nucleic Acids. Characteristics of Biological Molecules. Principle Elements
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Chemistry Biological Molecules Ch 2b Introduction to important molecules which comprise the structure and function of all living organisms
Biological Compounds Categories: Carbohydrates Lipids Proteins Nucleic Acids
Characteristics of Biological Molecules • Principle Elements • Ratio of Various Elements • Special Functional Groups
O O H H C O C O N H H Functional Groups Hydroxyl ( -OH ) Alcohols Aldehydes, Ketones Carbonyl (C=O) Carboxyl ( -COOH ) Carboxylic acids Amino ( -NH2 ) Amines
O O H H O P O S H Functional Groups Phosphate ( -H2PO4) Organic phosphates Sulfhydryl ( -SH) Thiols
Characteristics of Biological Molecules Monomer • Subunits that serve as building blocks • Connected by condensation reactions (dehydration) Polymers • Covalent bonding occurs • Solubility in Water
Monomers & Polymers Monomer Polymer
Dehydration Synthesis Monomers H HO H HO H2O Polymer
Dehydration Synthesis C6H12O6 + C6H12O6C12H22O11 + H2O
Hydrolysis Monomers H2O H HO
Hydrolysis C12H22O11 + H2O C6H12O6 + C6H12O6
Characteristics of Carbohydrates Principle Elements: C, H, & O H:O = 2:1 Many Hydroxyl Groups (-OH) Monomers: Monosaccharides Polymers: Polysaccharides Water Soluble
Function of Carbohydrates • Energy Metabolism • Structural Components • Cell-to-Cell Contacts and Recognition
Monosaccharides Chemical Formulas C6H12O6 C6H12O6
Monosaccharides Chemical Formulas C5H10O5 C5H10O4 deoxyribose
Disaccharides Lactose glucose + galactose Maltose glucose + glucose Sucrose glucose + fructose
Polysaccharides glycogen
Characteristics of Lipids • Principle Elements: C, H, & O • Some With P & N • H:O >>> 2:1 • Diverse Group of Biological Molecules • Water Insoluble
Function of Lipids • Energy Storage • Protection & Cushioning of Body Organs • Structural Components of Membranes • Chemical Messengers (hormones)
Major Types of Lipids • Triglycerides (neutral fats) • Phospholipids • Sterols • Waxes • Vitamins (A, D, E, K)
Triglycerides Fatty Acid Glycerol
Saturated Fats • Saturated with H+ • Most animal fats are saturated, ex. butter • Solid at room temp Glycerol Fatty Acids
Unsaturated Fats • Has one or more double bonds between • carbons • Most vegetable fats • Liquid at room temp
Phospholipids Hydrophilic head Hydrophobic tails
Steroids cholesterol
Your Cholesterol • Cholesterol: < 175 mg/dl • Triglycerides: 30-175 mg/dl • HDL: >35 • LDL: <130 • Cholesterol/HDL ratio: <4.5 indicates heart disease
Risk Factors for High Cholesterol • Family history of vascular disease • High levels of blood cholesterol • Smoking • Diabetes • Hypertension • Obesity
Lower Your Cholesterol • Eat healthy • Exercise • Lose wt. • Quit smoking • 1 glass wine or beer • Medication • Surgery
Characteristics of Protein • Principle Elements: C, H, O, & N • Monomers: Amino Acids • Polymers: Polypeptides or Proteins • Generally Water Soluble
Characteristics of Protein Functional Groups of Amino Acids • Carboxylic Acid (-COOH) • Amine (-NH2) • R-Groups (variable - 20 different kinds)
Functions of Protein • Enzymes • Structural Proteins • Chemical Messengers (Hormones) • Contractile • Antibodies
Levels of Protein Structure Primary structure Secondary structure Tertiary structure Quarternary structure
Levels of Protein Structure Primary structure: Linear sequence of amino acids NH3 Leu Cys Val Asp Phe COO Secondary structure: H-Bonds Alpha helix Beta Pleated sheet
Levels of Protein Structure Tertiary: 3D configuration Weak bonds between side chains Quartenary: Two or more polypeptides e.g. Hemoglobin (Hb)
Amino Acid Structure Central carbon Hydrogen atom O H H N C C OH H R Carboxyl group Amino group Variable R group
Carboxyl group of one aa Amino group of another aa Peptide bond Formation of Peptide Bonds Condensation reaction: +
Enzymes • Catalysts- speed up a reaction • Not used up by reaction • Decrease activation energy of a reaction • (activation energy is needed to break chemical bonds) Enzymatic reactions are affected by: Temperature pH Substrate conc. Enzyme conc.
Enzymes Are very specific for their substrate Substrates: Bind only to a restricted region of the enzyme (active site) Held in place by weak interactions (H-bonds) Specificity of enzyme: Compatible fit between the shape of the substrate and the shape of the active site Lock and key
Regulation of Enzymatic Activity