1. A COMPARATIVE STUDY OF THE HEAT OF COMBUSTION OF SUGAR AND FAT Elizabeth Hines (Background & Hypothesis) Edward Swanson (Methods & Protocol) Karishma Mehta (Deliverables) Lorraine Chua (Pitfalls) Bo Zeng (Equipment & Budget) BE210-101B2

2. Department of Bioengineering BE210-101B2 Background  Bioenergetics- The study of the transformation of energy in living organisms.  Bomb Calorimeter used to find the Heat of combustion(∆ c H 0 ) of a compound Hypothesis, Aim and Objective: We hypothesize that the heat of combustion of Palmitic acid will be higher than that of glucose. Elizabeth Hines  Glucose- A simple sugar that is an important energy source in living organisms and is a component of many carbohydrates.  Palmitic Acid- a solid saturated fatty acid obtained from palm oil and other vegetable and animal fats CH 3 (CH 2 ) 14 COOH  This study would perpetuate the importance of a well balanced diet coupled with an appropriate exercise routine.

3. Department of Bioengineering BE210-101B2 Methods & Protocol 1.Make a 1.000 gram pellet of Benzoic Acid in a bomb crucible, with a 10 cm fuse wire just above the pellet. 2.Pressurize the bomb with 25 atm of pure oxygen 3.Place the bomb in a calorimeter filled with 2000 grams of di- water and begin the rotation of the stirrer. 4.After a five minute wait, start logging the thermistor data. After five minutes of pre-period data, ignite the bomb with the ignition unit. Keep recording data until more that 5 minutes after temperature stabilization has been reached. 5.Repeat Steps 1-4 twice and analyze the temperature versus time graphs to restandardize W. 6.Repeat Steps 1-4 three times with palmitic acid and analyze the temperature versus time graphs to calculate ∆ c H 0. 7.Repeat Step 6 with Glucose. Edward Swanson

4. Department of Bioengineering BE210-101B2 Proposed Deliverables and Findings Heat of Combustion of different macronutrients. Source: Dietary Reference Intakes for Energy, Carbohydrate, Fibre, Fat, Fatty Acids, Cholesterol, Protein, And Amino Acid; Institute of Medicine; National Academies Press; Aug 1, 2005 Karishma Mehta The  H calculated from data in the lab should correspond to the literature values of  H for the sugar and the fat. The  H of sugar will be statistically lower than the  H of fat (p-value < 0.05). The temperature rise of water for the fat will be statistically higher than for the carbohydrate after ignition of the bomb calorimeter. Therefore, the temperature-time graphs for the two substances will differ, as shown on the right.

5. Department of Bioengineering BE210-101B2 Potential Pitfalls Methods Pitfall Difficulty in pressing the pellets of benzoic acid, palmatic acid and glucose resulting in inconsistent pellet masses Placement of the fuse wire and handling of the bomb resulting in misfiring Loss of water mass via evaporation Inaccuracy in acid correction due to incomplete removal of nitirc acid and sulfuric acid from calorimeter Statistical Pitfall Difficulty in the determination of points of the start of the temperature rise and the points of the temperature leveling after the rise from temperature-time graph Lorraine Chua

6. Department of Bioengineering BE210-101B2 Equipment/Materials, Budget & Justification Materials: -Par Instrument Model 1341 Oxygen Calorimeter w/ Stirrer and associated components -Par Instrument Model 1108 Oxygen Combustion Inner Container -Precision Temperature Sensor (LM135) -Biopac System, Biopac Pro Software -Par Model 2901 Ignition Unit -Parr Pellet Press -Sample crucible, ignition wire, stands and other associated components Bo Zeng Additional Equipment: -10 grams Palmitic Acid (Sigma-Aldrich) - $25.20 -30 grams Benzoic Acid (Sigma-Aldrich) - $12.40 -1 grams (D+) Glucose (Sigma – Aldrich) -$15.20 Justification: The two additional compounds from Sigma-Aldrich are used to compare the similarities and differences between milk fat (Palmitic Acid) and glucose. Benzoic Acid is used as a test standard. Palmitic Acid is the most common source of saturated fatty acids found in animals and plants.