A COMPARATIVE STUDY OF A COMPARATIVE STUDY OF THE HEAT OF COMBUSTION OF THE HEAT OF COMBUSTION OF

SUGAR AND FATSUGAR AND FAT

Elizabeth Hines (Background & Hypothesis)Edward Swanson (Methods & Protocol)Karishma Mehta (Deliverables)Lorraine Chua (Pitfalls)Bo Zeng (Equipment & Budget)

BE210-101B2

Department of Bioengineering

BE210-101B2

BackgroundBackgroundBioenergetics- The study of the transformation of energy in living organisms.

Bomb Calorimeter used to find the Heat of combustion(∆cH0) of a compound

Hypothesis, Aim and Objective:Hypothesis, Aim and Objective:We hypothesize that the heat of combustion of Palmitic acid will be higher than that of glucose.

Elizabeth Hines

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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 CH3 (CH2)14 COOHThis study would perpetuate the importance of a well balanced diet coupled with an appropriate exercise routine.

Department of Bioengineering

BE210-101B2

Methods & ProtocolMethods & 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 oxygen3. 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 ∆cH0.

7. Repeat Step 6 with Glucose.

Edward Swanson

Department of Bioengineering

BE210-101B2

Proposed Deliverables and FindingsProposed 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

Macronutrient Heat of Combustion (kcal/g)Starch 4.18Sucrose 3.94Glucose (Carbohydrate) 3.72Palmitic Acid (Fatty acid) 9.44

• 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.

Department of Bioengineering

BE210-101B2

Potential PitfallsPotential 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

Department of Bioengineering

BE210-101B2

Equipment/Materials, Budget Equipment/Materials, Budget & Justification& 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.