LAB 6: WORKSHOP ON BIOMOLECULES AND COMMON BIOCHEMICAL REACTIONS, TA VERSIONObjectives: By the end of this lab session, you should:1. Be able to recognize and identify various functional groups in common biomolecules.2. Understand the general idea of dehydration reactions in joining two biomolecules, and understand the corresponding reverse hydrolysis reactions. 3. Understand the structure of ester and amide bonds and the reactions involved in their formation and hydrolysis.4. Understand how amide bonds relate to amino acids and proteins and how ester bonds relate to fattyacids and triglycerides. 5. Know how oxidation of sulfhydryl groups creates disulfide bonds and understand the importance of disulfide bonds in joining peptide chains. 6. Have a better understanding of common biomolecules and some of their more common reactions. 7. Know a little more about biological oxidations and physiological buffer systems.Note: Bring your 107 lecture PowerPoint slide sets for organic chemistry and functional groups/biomolecules along for this exercise.SECTION 1: REMINDER ABOUT BIOCHEMICALLY IMPORTANT FUNCTIONAL GROUPSLast week, we learned how to recognize the most important functional groups on biomolecules (listed below). You need to be able to recognize them in large molecules and know and understand the types of reactions they undergo. *Remember that at physiological pH, carboxylic acids are ionized (COO–; A– form). For example, citric acid has 3 COOH groups, all of which are ionized. We usually refer to it as citrate (to denote that it is ionized). Phosphate groups (phosphoric acid derivatives) are also ionized. The same is true for the basicamines, which are protonated (remember, bases accept protons) at physiological pH (-NH3+; HA form). However, for understanding the reactions these groups undergo, it is easier now to think of them as actual protonated acids (COOH) and nonprotonated amines (-NH2). Just keep in mind that they don’t actually look as such in cells.Biochem 107L6-2PROBLEM 1: Some biomolecules we will come to appreciate as we begin biochemistry are listed below. Circle all functional groups and identify them (Note: For the purpose of this exercise, nitrogen atoms and NH groups within a ring are not considered functional groups). You may take a picture of this page with the functional groups circled and identified to insert into your lab report.Biochem 107L6-3Amino AcidsShown as they exist at physiological pH (~7.4)Biochem 107L6-4SECTION 2: OXIDATION AND REDUCTION OF CARBONThis is very important! Only a brief overview is presented here. We’ll go over this topic again in more detail during lectures on carbohydrate oxidation. Oxidation of carbon atoms can be thought of as one of the following:- loss of electrons- loss of a hydrogen atom- addition of an oxygen atom- increase in oxidation number of carbon Reduction is the opposite of oxidation:- gain in electrons- gain in hydrogen atoms- loss of oxygen atom- decrease in oxidation number of carbon.The various oxidation states of carbon are shown below. Oxidations move from left to right, and reductions move from right to left. The final oxidation to form carbon dioxide yields completely oxidized carbon; this reaction is important in cellular energy metabolism. SECTION 3: DEHYDRATION AND HYDROLYSIS REACTIONS OF BIOMOLECULES Dehydration reactions are reactions in which water is removed. In some cases, an entire molecule of water is removed from the same compound (an H from one C atom and an OH from an adjacent C atomto give a new double bond). Fatty acid synthesis (see problem above) involves such a reaction. In many cases, however, dehydration reactions are used to join two compounds. These reactions are also known as condensation reactions. In a condensation reaction, one molecule gives up an H and the other molecule gives up an OH, with a bond forming between the two molecules where the water was lost. Formation of ester and amide bonds involves this type of reaction. PROBLEM 2: Beginning with the compound below (acetoacetic acid), draw the consecutive full structures that would result from the 3 series of reactions described below. Draw these reactions by hand and take a picture to insert into your lab report.1) reduction of the keto group on carbon 3 to an alcohol (addition of 2 H atoms)2) then, dehydration reaction involving carbon atoms 2 and 3 3) finally, reduction of the resulting double bond to a single bond (addition of 2 H atoms)Biochem 107L6-5SECTION 4: ESTERS AND AMIDES Ester bonds and amide bonds are absolutely vital to life, so we need to understand their structures and how they are formed and broken. As an example, metabolic energy derived from oxidation of foodstuffs is temporarily stored in cells in the high-energy phosphate ester bonds of adenosine triphosphate (ATP). Triglycerides (fat; the major storage form of foodstuffs) contain three fatty acids esterified to a glycerol molecule (see below). Amino acids are the building blocks of proteins, and they are connected to one another by amide (peptide) bonds to form proteins. Bond formation for both esters and amides involves the removal of water from two functional groupsthat combine in the process. One functional group loses an OH and the other loses an H. These bonds can be cleaved by the addition of water across them (the reverse of the formation reactions), giving back the original compounds. Such reactions are the opposite of dehydration reactions, and they are called hydrolysis reactions. Hydrolysis reactions are common in metabolism. Esters are formed when an alcohol combines with a carboxylic acid. Water is removed in this condensation reaction. The alcohol and carboxylic acid can be regenerated by a hydrolysis reaction (breaking the ester bond by addition of water). Fatty acids are the major storage form of energy substrates in our bodies, and they are stored as components of triglycerides. Three fatty acids are esterified to the three OH groups of glycerol, a polyalcohol. The structures of glycerol and a fatty acid are given below. H2C-OH HC-OH CH3(CH2)14COOHH2C-OHglycerol palmitic acid (a saturated fatty acid)Palmitic acid is a saturated fatty acid. Saturated means that, except for the carboxyl carbon, all the carbon atoms are maximally reduced. Many fatty acids, however, are unsaturated, that is, they contain one or more double bonds. Fatty acids with one double bond are monounsaturated; those