KIN 292 1st Edition Lecture 3 Outline of Last Lecture I Organization of the Human Body II Homeostasis A Central Organizing Principle of Physiology III The Diabetes Epidemic Outline of Current Lecture I Biomolecules a Molecules synthesized by living things b Contain carbon 4 unpaired electrons II Four basic types a Carbohydrates b Lipids c Amino acids and proteins d Nucleotides Current Lecture Biomolecules Unpaired electrons are shared between atoms to form covalent bonds Chem Review p 22 Is this molecule polar or nonpolar These notes represent a detailed interpretation of the professor s lecture GradeBuddy is best used as a supplement to your own notes not as a substitute Its polar because one of the atoms oxygen which is negative but strong binds the other hydrogen which is positive but weak Polar vs Nonpolaro Polarity affects diffusion of cells and your hormones o Fats are always nonpolar because of their covalent bond which means they share electrons equally o Water is polar because of the oxygen element very electronegative o Glucose and proteins are also polar o Example Steroids are a fat so they are non polar and made on demand Carbohydrates Composed of carbon hydrogen and oxygen General formula Cn H2O n CH2O n Primary role in body energy source Three types o Monosaccharides o Disaccharides covalent bonding of 2 monosaccharides Sucrose lactose o Polysaccharides covalent bonding of several monosaccharides Glycogen cellulose Monosaccharides o Note the hydroxyl groups These make carbohydrates polar o Three different monosaccharides with the same chemical formula C6H12O6 o Form ring structures Condensation vs Hydrolysis o Formation synthesis of sucrose from glucose and fructose is a condensation reaction meaning water is produced Common for synthesis of almost all biomolecules Two elements make up water gas to liquid Why is it necessary to remove H and OH from the respective monosaccarides So a covalent bond can be formed between glucose and fructose o Bond is between carbon Pulls hydrogen away and then they stick and hold onto each other referring to the diagram o Breakdown of sucrose in your stomach to glucose and fructose is a hydrolysis reaction meaning water is used to break the bond Hydrolysis is common for almost all breakdown reactions of biomolecules Two items are broken down o Returning the H referring to picture Glycogen a polysaccharide Glucose is stored as glycogen in muscles and liver by the process of glycogenesis It s a stored energy source Store max of about 500 g in body can slightly increase with glycogen loading procedures When glucose cannot be stored as glycogen or used immediately for energy it is converted to fat Like gas or fuel Cellulose a polysaccharide we cannot digest and absorb it because we cannot hydrolyze the bonds between glucose units most abundant natural resource 75 billion tonnes annually bio polysaccharide with hierarchical chiral structure stable and physiologically inert Lipids Also composed of carbon hydrogen and oxygen o Nonpolar covalent bonds o Hydrophobic Five classes with examples of roles in body o Triglycerides energy o Ketones produced when glucose use is limited Too much ketone is not good for your body o Phospholipids structure transport o Eicosanoids intracellular signaling o Steroids hormones membrane structure Cholesterol Triglycerides o Stored in fat pads mostly unlimited storage capacity o Triglyceride glycerol three fatty acids o Glycerol three carbon alcohol o Fatty acid long chain of many C and H atoms containing even number of carbons with only 2 oxygen atoms located at one end Can be saturated or unsaturated Ketones o In diabetes or low carbohydrate diets o When adequate amounts of glucose are unavailable as an energy source extra hydrolysis of triglycerides in adipose tissue occurs and much Free fatty acids are released in blood o Some free fatty acids converted to ketones by the liver o Acetoacetic acid acetone hydroxybutyric acid o Buildup ketosis ketoacidosis Hydrophobic nonpolar tails o Acetone breath Glyc Phospholipids erol two fatty acid back chains o Phospholipids are amphipathic molecules bone Hydrophilic polar o Polar head and Nonpolar tail head phosphatecontaining group o Reaction of phospholipids with water creates unique structures o Surfactant Phospholipid in the lungs that prevents lung collapse Micelles allow lipoproteins cholesterol to travel in aqueous plasma Eicosanoids Modified fatty acids that function in intracellular communication We ll see them doing this in about a month Derived from arachidonic acid 20 carbon polyunsaturated fatty acid found in cell membranes Examples Prostaglandins thromboxanes Steroids All steroids are derived from cholesterol and have the same base structure of 3 six carbon rings and 1 five carbon ring They vary in what is attached to the rings Examples Estrogen testosterone aldosterone Proteins Polymers chemical chain of amino acids Amino acids Building blocks of proteins 20 different kinds of amino acids o Peptide bonds Formation of a peptide bond by a condensation reaction Proteins have 50 amino acids Shorter chains are called peptides Levels of Protein Structure Primary order of the sequence of amino acids connected by peptide bonds Secondary folding pattern caused by weak hydrogen bonds between amino and carboxyl groups in the polypeptide chain P 31 chem review Tertiary folding pattern caused by various bonds and forces among R groups in the chain Quaternary when multiple polypeptide chains make up a protein Ex hemoglobin 4 chains Proteins can be classified as Fibrous or Globular Examples of roles of proteins intracellular chemical messengers receptors carrier proteins enzymes transport proteins Nucleotides and Nucleic Acid Classifications o Energy transfer o Chemical messengers o Genetic material Nucleotide structure o Phosphate group s almost always o Five carbon carbohydrate o Either Ribose o Deoxyribose Base containing carbon nitrogen ring o Pyrimidines cytosine thymine uracil o Purines adenine guanine Energy Transferring Nucleotides o Adenosine di tri phosphate ADP ATP Adenine ribose 2 or 3 phosphates Adenine ribose adenosine o Nicotinamide adenine dinucleotide NAD AKA Vitamin B3 or Niacin o Flavin adenine dinucleotide FAD AKA Vitamin B2 or Riboflavin Cyclic Nucleotides o Chemical messengers o Form a ring with the phosphate group o cAMP and cGMP are messenger molecules Nucleic Acids o Store and Express the Genetic Code o DNA Carbohydrate deoxyribose Double