What is this? Organic Compound Living matter or arising from living matter ___________ elements chemically combined

Biochemistry: Essentials for Life Inorganic compounds Lack carbon Tend to be simpler compounds Example: ________________ Organic compounds Contain carbon and hydrogen Example: ________________

Carbohydrates Sugars and starches Contain C, H, and O (CH 2 O) n Three classes Monosaccharides Disaccharides Polysaccharides

Carbohydrates Functions Major source of cellular fuel (e.g., glucose) Provides ___________________________ (b) Disaccharides GlucoseFructose Sucrose Glucose Maltose Galactose Glucose Lactose

Lipids C ontain ____________________(less than in carbohydrates), and sometimes __________ Insoluble in water Main functions ______________ Fatty acids are the building block of lipids Bonds are formed when water is released

Figure 2.17 (a) Generalized structure of all amino acids. (b) Glycine is the simplest amino acid. (c) Aspartic acid (an acidic amino acid) has an acid group (—COOH) in the R group. (d) Lysine (a basic amino acid) has an amine group (–NH 2 ) in the R group. (e) Cysteine (a basic amino acid) has a sulfhydryl (–SH) group in the R group, which suggests that this amino acid is likely to participate in intramolecular bonding. Amine group Acid group Polymers of amino acids (20 types) Joined by ___________ bonds Contain ___________________________ Proteins

Figure 2.18 Amino acid Dipeptide Dehydration synthesis: The acid group of one amino acid is bonded to the amine group of the next, with loss of a water molecule. Hydrolysis: Peptide bonds linking amino acids together are broken when water is added to the bond. + Peptide bond

Figure 2.20 Activation energy required Less activation energy required WITHOUT ENZYMEWITH ENZYME Reactants Product Reactants Enzymes Biological catalysts Lower the activation energy, increase the speed of a reaction (millions of reactions per minute!)

Figure 2.21, step 3 Substrates (S) e.g., amino acids Enzyme (E) Enzyme-substrate complex (E-S) Enzyme (E) Product (P) e.g., dipeptide Energy is absorbed; bond is formed. Water is released. Peptide bond Substrates bind at active site. Enzyme changes shape to hold substrates in proper position. Internal rearrangements leading to catalysis occur. Product is released. Enzyme returns to original shape and is available to catalyze another reaction. Active site + H2OH2O 12 3

Nucleic Acids DNA and RNA Largest molecules in the body Contain C, O, H, N, and P Building block = nucleotide 1. ____________________________ 2. ________________________ 3. ________________________