MACROMOLECULES OF THE HUMAN BODY TYPES OF MACROMOLECULES Carbohydrates Proteins Lipids (Fats) Nucleic Acids MACROMOLECULE 1: CARBOHYDRATES Carbohydrates contain 3 elements: C, H, and O These elements are found in a 1:2:1 ratio Carbohydrate Carbo = Carbon (C) Hydrate = Water (H20) C H20 = C, H, and O in a 1:2:1 ratio CARBOHYDRATES ARE COMPOSED OF RINGS OF CARBON, HYDROGEN, AND OXYGEN CARBOHYDRATES: MONOSACCHARIDES Monosaccharides Mono = one saccharide = sugar Characteristics of a Monosaccharide Are the simplest sugars Are single ring structures Typically have a chemical formula C6H12O6 EXAMPLES OF MONOSACCHARIDES Glucose Glucose, fructose, and galactose are all monosaccharides with the chemical formula C6H12O6. Isomer – substances that have the same chemical formula, but a different structural formula EXAMPLES OF MONOSACCHARIDES Deoxyribose (C5H10O4) and Ribose (C5H10O5) are not true isomers as they do not have the exact same chemical or structural formulas. Can you find the difference in the structural formulas of deoxyribose and ribose? How do you suppose deoxyribose got it’s name? CARBOHYDRATES: DISACCHARIDES Sucrose = table sugar Lactose = milk sugar Maltose = malt sugar (barley products) DISACCHARIDE FORMATION Disaccharides are the result of the connection of two monosaccharides by dehydration synthesis. DEHYDRATION SYNTHESIS EQUATION C6H12O6 + C6H12O6 = C12H22O11 + H2O C12H22O11 + C12H22O11 = C24H42O21 + H2O C24H42O21 + C24H42O21 = C48H82O41 + H2O CARBOHYDRATES: POLYSACCHARIDES Polysaccharides are the result of connection of many monosaccharides by dehydration synthesis. The general formula for polysaccharides can also be represented as (C6H10O5)n where 40≤n≤3000 Examples of polysaccharides are starch (plants/energy), glycogen (animals/energy), cellulose (plants/fiber), and chitin (animals/fungi/protection) POLYSACCHARIDES: STARCH Starches are glucose polymers. Amylose starches consists of a linear chain of several hundred glucose molecules and Amylopectin starches are a branched molecule made of several thousand glucose units (every chain 24–30 glucose unit). Starches are insoluble in water. They can be digested by hydrolysis, catalyzed by enzymes called amylases. Humans and other animals have amylases, so they can digest starches. Potato, rice, wheat, and corn are major sources of starch in the human diet. The formation of starches are the way that plants store glucose. POLYSACCHARIDES: GLYCOGEN Glycogen is a polysaccharide that is found in animals and is composed of a branched chain of glucose residues. It is stored in liver and muscles. POLYSACCHARIDES ILLUSTRATED CELLULOSE The structural component of plants are formed primarily from cellulose. Wood is largely cellulose and lignin, while paper and cotton are nearly pure cellulose. Cellulose is a polymer made with repeated glucose units bonded together. Humans and many other animals lack an enzyme to break these linkages, so they do not digest cellulose. Certain animals can digest cellulose, because bacteria possessing the enzyme are present in their gut. The classic example is the termite. CHITIN Chitin is one of many naturally occurring polymers. It is one of the most abundant natural materials in the world. Over time it is bio-degradable in the natural environment. Its breakdown may be catalyzed by enzymes called chitinases, secreted by microorganisms such as bacteria and fungi, and produced by some plants. Some of these microorganisms have receptors to simple sugars from the decomposition of chitin. If chitin is detected, they then produce enzymes to digest it by cleaving the glycosidic bonds in order to convert it to simple sugars and ammonia. CARBOHYDRATES IN FOOD Fruits Vegetables Nuts Grains Seeds/Nuts Pasta FUNCTIONS OF CARBOHYDRATES Providing energy and regulation of blood glucose Sparing the use of proteins for energy Breakdown of fatty acids and preventing ketosis (use of cellular glycogen for energy) Biological recognition processes Flavor and Sweeteners Dietary fiber MACROMOLECULE 2: PROTEINS Proteins contain the elements carbon, hydrogen, oxygen, nitrogen, and sometimes sulfur PROTEINS AND AMINO ACIDS Proteins are composed of amino acids linked together by dehydration synthesis AMINO ACIDS AND R-GROUPS THE PEPTIDE BOND POLYPEPTIDES VS. PROTEINS Polypeptide is a single linear chain of amino acids bonded together by peptide bonds. PROTEINS VS. POLYPEPTIDES Protein molecules consist of one or more polypeptides put together typically in a biologically functional way. PROTEIN STRUCTURE FUNCTIONS OF PROTEINS Required for building and repair of body tissues (including muscle) Enzymes, hormones, and many immune molecules are proteins Essential body processes such as water balancing, nutrient transport, and muscle contractions require protein to function. Protein is a source of energy. Protein helps keep skin, hair, and nails healthy. Protein, like most other essential nutrients, is absolutely crucial for overall good health PROTEINS AS ENZYMES The best-known role of proteins in the cell is as enzymes, which catalyze chemical reactions. Enzymes are usually highly specific and accelerate only one or a few chemical reactions. Enzymes carry out most of the reactions involved in metabolism, as well as manipulating DNA in processes such as DNA replication, DNA repair, and transcription. PROTEINS IN FOOD Red meat Chicken Fish Pork Eggs Dairy Beans Nuts Seeds MACROMOLECULE 3: LIPIDS Lipids are also known as fat Lipids may contain the elements C, H, O, N, P The main lipid consumed in vegetable oil and animal fats is a triglyceride. Triglycerides are composed of 3 (tri) fatty acids and one glycerol (glyceride). TRIGLYCERIDE FORMATION: DEHYDRATION SYNTHESIS FUNCTIONS OF LIPIDS The main biological functions of lipids include energy storage and as structural components of cell membranes (phospholipids). LIPIDS IN FOOD Meats Dairy Pastries Oils Dressings Processed foods Fast foods MACROMOLECULE 4: NUCLEIC ACIDS There are two nucleic acids: Deoxyribonucleic acid (DNA) Ribonucleic acid (RNA) Nucleic acids contain the elements C, H, O, N, P NUCLEIC ACIDS AND NUCLEOTIDES DNA and RNA are composed of nucleotides Nucleotides are composed of a sugar, a phosphate group, and a nitrogenous base DNA DNA nucleotides are composed of the sugar deoxyribose, phosphoric acid, and one of four nitrogenous bases The four nitrogenous bases of DNA are Adenine (A), Cytosine (C), Thymine (T), and Guanine (G) Adenine forms two hydrogen bonds with Thymine Guanine forms three hydrogen bonds with Cytosine DNA RNA RNA nucleotides are composed of the sugar ribose, phosphoric acid, and one of four nitrogenous bases The four nitrogenous bases of DNA are Adenine (A), Cytosine (C), Uracil (U), and Guanine (G) Adenine bonds with Uracil Guanine bonds with Cytosine RNA is a single stranded molecule DNA VS. RNA DNA REPLICATION In order for a cell to divide during the processes of mitosis (body cells) or meiosis (sex cells), the cell must first replicate (duplicate) it’s DNA. TRANSCRIPTION: DNA TO RNA Transcription: the process of making RNA from the DNA found within the nucleus of a eukaryotic cell TRANSLATION: RNA TO PROTEINS Translation: the process of making proteins from RNA within the cytoplasm of the cell TRANSLATION: RNA TO PROTEINS MONOMERS AND POLYMERS Polymer: a large molecule (macromolecule) composed of repeating structural units Monomer: a small molecule that may bind chemically to other monomers to form a polymer MACROMOLECULE POLYMERS MONOMERS Carbohydrates Polysaccharides Monosaccharides Proteins Proteins/Polypeptides Amino Acids Lipids Triglycerides/Phospholipids Glycerol + Fatty Acids Nucleic Acids DNA and RNA Nucleotides MACROMOLECULES DIGESTION OF MACROMOLECULES In order for the human body to utilize the macromolecules it consumes in a meal, it must first break down the nutrients into their simplest form, monomers! This process is achieved in the digestive system by way of enzymes Once the macromolecules are broken into monomers they can be absorbed into the blood stream and transported to the cells where they will continue to perform their functions DIGESTION, ENZYMES, AND HYDROLYSIS Digestion is controlled by enzymes (specialized proteins) Enzymes are biological catalysts Catalysts initiate or speed up a reaction without becoming part of the reaction Proenzymes – inactive enzyme precursor Digestion is accomplished by hydrolysis Hydrolysis is the opposite of dehydration synthesis DIGESTION, ENZYMES, AND HYDROLYSIS Hydrolysis: Hydrolysis is a chemical process in which a certain molecule is split (lysis) into two parts by the addition of a molecule of water (hydro). One fragment of the parent molecule gains a hydrogen ion (H+) from the additional water molecule. The other group collects the remaining hydroxyl group (OH−). HYDROLYSIS OF TABLE SUGAR THE PROCESS OF DIGESTION VIDEO The Enzymes of Digestion (2:46) http://www.youtube.com/watch?v=AEsQxzeAry8 DIGESTIVE ENZYMES Carbohydrates DIGESTIVE ENZYMES Proteins DIGESTIVE ENZYMES Lipids and Nucleic Acids Pancreatic nuclease enzymes digest nucleic acids (DNA and RNA) to nucleotides in the duodenum. Membrane-bound nucleotidase enzymes in the epithelial cells of the ileum digest the nucleotides to sugar, base and phosphate, which are absorbed. ENZYMES IN ACTION MICELLE LACTEAL CHYLOMICRONS Lipoproteins: 85-92% triglycerides, 6-12% phospholipids, 1-3% cholesterol, 1-2% proteins