After students complete the pH lab, they will have a basic understanding of which substances are classified as acids or bases as recorded in the pH Lab Data table. Students will also observe and be able to describe the reaction between an acid and a base when they are added together. After discussing what carbohydrates are and looking at the molecular models in the power point, students will identify simple and complex carbohydrates by stating which foods contain them. Contains carbon (Carbon dioxide & carbon monoxide contain carbon, but they are inorganic) Carbon is electroneutral Means it never loses or gains electrons, it always shares Organic compounds in the body include: Carbohydrates Lipids Proteins Nucleic Acids Contain carbon, hydrogen, and oxygen Includes sugars and starches Their major function is to supply a source of cellular food Classified as monosaccharides (one sugar), disaccharide (two sugars), and polysaccharide (many sugars) Figure 2.13a Monosaccharides or simple sugars Monosaccharides are the building blocks of all other carbohydrates Figure 2.13a Disaccharides or double sugars Disaccharides are formed when 2 monosaccharides are joined by a dehydration synthesis reaction. Disaccharides are decomposed back into monosaccharides by a hydrolysis reaction. (water added) Polysaccharides or polymers are long chains of simple sugars Figure 2.13c Important polysaccharides to the body – starch and glycogen – both are polymers of glucose Starch Storage carbohydrate of plants Glycogen Storage carbohydrate of animals Stored in muscles and the liver When blood sugar levels drop, liver cells break down glycogen and release glucose into the blood Starch Monosacchrides After discussing what carbohydrates are, looking at the molecular models in the power point, and performing the starch lab, students will identify simple and complex carbohydrates, and state which foods contain them. Students will be able to test for the presence of starch in foods. After discussing what carbohydrates are, looking at the molecular models in the power point, and performing the starch lab, and Simple sugar lab students will identify simple and complex carbohydrates, and state which foods contain them. Students will be able to test for the presence of starch and simple sugars in foods. NOW! After discussing what lipids are and looking at the molecular models in the power point, students will identify lipids and state which foods contain them. Students will be able to explain why lipids are important to our bodies. Insoluble in water Contain C, H, and O, but the proportion of oxygen in lipids is less than in carbohydrates Examples: Neutral fats or triglycerides Oils Phospholipids Steroids Waxes Fats store energy, help to insulate the body, and cushion and protect organs 23 lipids are important parts of biological membranes and waterproof coverings Oils (liquid) unsaturated fat Fats (solid) Saturated fat Waxes Prevents water loss in plants Earwax Phospholipids found in cell membranes 25 Saturated fatty acids have the maximum number of hydrogens bonded to the carbons (all single bonds between carbons) Unsaturated fatty acids have less than the maximum number of hydrogens bonded to the carbons (a double bond between carbons) 26 Single Bonds in Carbon chain Double bond in carbon chain 27 Composed of three fatty acids bonded to a glycerol molecule Figure 2.14a Body’s most efficient form for storing large amounts of usable energy Found mainly beneath the skin and around organs Insulates deeper body tissues from heat loss and protects from trauma Figure 2.14a Women usually have a thicker subcutaneous fatty layer (more insulation) than men – why women are more successful English Channel swimmers Most animal fats have a high proportion of saturated fatty acids & exist as solids at room temperature (butter, margarine, shortening) 31 Most plant oils tend to be low in saturated fatty acids & exist as liquids at room temperature (oils) ) 32 • • • Cell membranes are made of lipids called phospholipids Phospholipids have a head that is polar & attract water (hydrophilic) Phospholipids also have 2 tails that are nonpolar and do not attract water (hydrophobic) 33 Phospholipids – modified triglycerides with two fatty acid groups and a phosphorus group Figure 2.14b Amphipathic – has both polar and nonpolar parts Chief component of cell membranes Nonpolar hydrocarbon portion (tail) interacts with only other nonpolar molecules Phosphorus part is polar and attracts polar or charged particles like water and ions Steroids – flat molecules with four interlocking hydrocarbon rings Figure 2.14c Cholesterol is the structural basis for all the body’s steroids Found in cell membranes Raw material of vitamin D, bile salts, sex hormones, and adrenal cortical hormones. Estrogen & testosterone are steroids Figure 2.14c They are variants of testosterone Some athletes use them to build up their muscles quickly They can pose serious health risks 38 Eicosanoids – 20-carbon fatty acids found in cell membranes – most important is the prostaglandins which has a role in blood clotting, inflammation, and labor contractions Fat-soluble vitamins – vitamins A, E, and K Lipoproteins which transport fatty acids and cholesterol in the bloodstream Figure 2.14c trans·lu·cent/transˈlo͞osnt/ Adjective: (of a substance) Allowing light, but not detailed images, to pass through; semitransparent. After discussing what proteins are and looking at the molecular models in the power point, students will be able to identify proteins, state which foods contain them, describe their functions and state their building blocks. Students will also be able to explain the function of enzymes. Basic structural material of the body Other proteins play vital roles in cell function Proteins include Enzymes Hemoglobin Contractile proteins of the muscle All proteins contain carbon, oxygen, hydrogen, and nitrogen, many contain sulfur and phosphorus Amino acids are the building blocks of protein, contains an amino group and a carboxyl group 20 common types of amino acids Figure 2.15a-c Figure 2.15d, e 46 Proteins are long chains of amino acids joined together by dehydration synthesis, resulting in a peptide bond Most proteins are large molecules containing from 100 to 10,000 amino acids! Figure 2.16 Primary – amino acid sequence Secondary – alpha helices or beta pleated sheets Tertiary – superimposed folding of secondary structures Quaternary – polypeptide chains linked together in a specific manner Figure 2.17a-c Figure 2.17d, e Fibrous proteins Extended and strandlike proteins Examples: keratin, elastin, collagen, and certain contractile fibers Globular proteins Compact, spherical proteins with tertiary and quaternary structures Examples: antibodies, some hormones, and enzymes Reversible unfolding of proteins due to drops in pH and/or increased temperature Figure 2.18a Irreversibly denatured proteins cannot refold and are formed by extreme pH or temperature changes Figure 2.18b Changes in temperature & pH can denature (unfold) a protein so it no longer works Cooking denatures protein in eggs Milk protein separates into curds & whey when it denatures 55 Help other proteins to achieve their functional three-dimensional shape Maintain folding integrity Assist in translocation of proteins across membranes Promote the breakdown of damaged or denatured proteins Most are globular proteins that act as biological catalysts Some enzymes are pure protein, some have a cofactor, usually a metal ion or an organic molecule derived from vitamins Enzymes are chemically specific Frequently named for the type of reaction they catalyze Enzyme names usually end in -ase Lower activation energy = energy needed to start a chemical reaction Figure 2.19 Enzyme binds with substrate Product is formed at a lower activation energy Substrate=reactants of an enzyme catalyzed reaction Product: compound produced by a chemical reaction Product is released Active site Amino acids 1 Enzyme (E) Substrates (s) H20 Enzymesubstrate complex (E–S) 2 Free enzyme (E) 3 Peptide bond Internal rearrangements leading to catalysis Dipeptide product (P) Figure 2.20 62 • • • • Blood sugar level is controlled by a protein called insulin Insulin causes the liver to uptake and store excess sugar as Glycogen The cell membrane also contains proteins Receptor proteins help cells recognize other cells 63 INSULIN Cell membrane with proteins & phospholipids 64 After discussing what nucleic acids are and looking at the molecular models in the power point, students will identify them, their building blocks and explain the importance of nucleic acids in our bodies and how they function. Composed of carbon, oxygen, hydrogen, nitrogen, and phosphorus Their structural unit, the nucleotide, is composed of Nitrogen-containing base, a pentose sugar, and a phosphate group Five nitrogen bases contribute to nucleotide structure – adenine (A), guanine (G), cytosine (C), thymine (T), and uracil (U) Two major classes – DNA and RNA DNA has the bases A, G, C, &T. RNA has the bases A, G, C, & U. Double-stranded helical molecule found in the nucleus of the cell Replicates itself before the cell divides, ensuring genetic continuity Provides instructions for protein synthesis Figure 2.21a Figure 2.21b Single-stranded molecule found in both the nucleus and the cytoplasm of a cell Uses the nitrogenous base uracil instead of thymine Three varieties of RNA: messenger RNA, transfer RNA, and ribosomal RNA Source of immediately usable energy for the cell Adenine-containing RNA nucleotide with three phosphate groups Figure 2.22 Figure 2.23 Lab next time.