Chapter TwoEnergyEnergyHeatUnits of EnergyUnits of EnergyEnergy and NutritionEnergy and NutritionCaloric ValuesCaloric ValuesCaloric ValuesUniform LabelingTrue or False?Expending EnergyExpending EnergyWeight Gain and LossExample ProblemExample ProblemExampleCalculated vs. LabelArby’s MealPercentagesTemperature ScalesTemperature ScalesTemperature ScalesSpecific HeatSpecific HeatSpecific HeatStates of MatterStates of MatterStates of MatterChanges of StateChanges of StateChange of StateHeating Curve for WaterCalculating HeatChapter TwoLearning GoalsUnderstand the forms of energyCalculate caloric values for foodConvert temperatures between all three scalesCalculate heat gained using a specific heatDescribe the characteristics for all three states of matterDescribe the changes in state between each phase and the energy involvedEnergyWork = an activity that requires energyEnergy = the ability to do workAll energy can be described as either potential energy or kinetic energyPotential Energy = stored energy Kinetic Energy = energy of motionEnergyConverting between the two forms of energy occurs all of the time.Ex) Hooking up a battery to a portable music player – the batteries PE is converted into KE.Ex) Riding a bicycle up a hill – your KE is being converted into PE.HeatHeat is the energy associated with the motion of particles in a substance.Temperature is the measurement for heat and is proportional to the motions of the molecules in the object.Thus, a cold object has slower moving molecules and a warm object has faster moving molecules.Units of EnergySI unit of energy is called the Joule (J).A Joule is a relatively small unit, so more commonly will see kilojoules (kJ).Sitting in your chair your body is consuming approximately 7 kJ per minute.Units of EnergyOlder unit of energy is the calorie (cal).A calorie is defined as the amount of energy required to raise 1 gram of water by 1oC.A calorie is also a small unit, so more commonly will see kilocalories (kcal).Conversion between the two units:1 cal = 4.184 J (exact)Energy and NutritionA Nutritional Calorie (note the uppercase “C”) is actually a kilocalorie.Thus, 150 Calories is really 150 kcal.The Caloric content of food is determined by the use of a device called a calorimeter.The food is combusted in the “bomb” and the heat released is absorbed by the water.Energy and NutritionCaloric ValuesThe caloric values of food are divided into the three types of food: carbohydrates, proteins, and fats.Carbohydrate = 4 kcal/gProtein = 4 kcal/gFat = 9 kcal/gIt should be noted that these are all average values as there are many different types of carbohydrates, proteins, and fats.Caloric ValuesThese values can be used to calculate the total Calories in any food item.Caloric ValuesFrom the label, the muffin contains 12g of fat, 31g of carbohydrate, and 5g of protein.12g x (9 kcal/g) = 108 kcal31g x (4 kcal/g) = 124 kcal5g x (4 kcal/g) = 20 kcalTotal = 252 kcal (amounts usually rounded to 2 sig. figs.)Uniform LabelingIn 1990, the NLEA was passed to require that food labels contain certain information.% Daily Value – reflects percents based on a 2,000 Calorie diet.Good resource for finding caloric contents of foods including fast foods can be found at: http://www.nutritiondata.com/True or False?Many “claims” by manufacturers are also regulated.Fat-free means that a product contains zero grams of fat.Light – the food must contain either half the fat, one-third the calories, or half the salt of the regular version.Serving sizes are at the discretion of the manufacturer. All carbohydrate sources should be treated the same way with respect to Calories.Expending EnergyWhether at sleep or being very active, our bodies are expending energy.Energy is needed for:Chemical reactions in the bodyMaintaining body temperatureMuscle contractionNerve impulsesAnd many more thingsExpending EnergyAverages for males and females varyFemale approximately 2200 kcal/dayMale approximately 3000 kcal/dayMetabolism CalculatorEnergy expended varies as wellSleeping = about 60 kcal/hrSitting = about 100 kcal/hrWalking = about 200 kcal/hrSwimming = about 500 kcal/hrRunning = about 750 kcal/hrWeight Gain and LossCaloric Balance = Calories consumed minus the Calories expendedWeight Gain occurs when former exceeds the latter.To lose weight requires that the latter exceed the former.To lose one pound of fat (454g) requires that you burn approximately 3500 Calories per week more than you consume.Example ProblemA particular person’s diet consists of 80g of protein, 350g of carbohydrate, and 100g of fat per day.Total Calories = 80g x (4 kcal/g) + 350g x (4 kcal/g) + 100g x (9 kcal/g) = 2620 kcalThis person sleeps 8 hours, walks 1 hour and sits 15 hours in one day.Energy expended = 8 hr x (60 kcal/hr) + 1 hr x (200 kcal/hr) + 15 hr x (100 kcal/hr) = 2180 kcalExample ProblemThe caloric balance = 2620 kcal – 2180 kcal = +440 kcalThis person would potentially gain one pound of fat for every eight days at this rate.Assignment: Calculate total calories for an all fast food diet.ExampleLunch at Arby’sBeef & CheddarCurly FriesSprite, 16 ozCalories (on label) / Fat / Carbs / Protein440Cal / 21g / 44g / 22g336Cal / 18g / 39g / 4g197Cal / 0g / 50g / 0gCalculated vs. LabelCalculated calories will not always agree with actual calories on label due to rounding issues. To find % of fat, carbohydrate, and protein – use calculated calories from gram amounts.Arby’s MealTotal Fats = 21g + 18g + 0g = 39g39g x 9 Cal /g = 351 CalTotal Carbs = 44g + 39g + 50g = 133g133g x 4 Cal/g = 532 CalTotal Protein = 22g + 4g + 0g = 26g26g x 4 Cal/g = 104 CalTotal (Calculated) Calories =351 Cal + 532 Cal + 104 Cal = 987 Cal(Actual total = 973 Cal)Percentages35.6% 100 Cal 987Cal 351 Fat % 53.9% 100 Cal 987Cal 532 Carbs % 10.5% 100 Cal 987Cal 104 Protein % Temperature ScalesTemperature is a measure of how hot or cold a substance is.Heat always flows from warmer objects to colder ones.Temperatures are usually recorded in one of three scales: Fahrenheit, Celsius, or Kelvin.Temperature ScalesThe Fahrenheit scale is used commonly in the USA. The Celsius scale