Objective: Explain ...

How we calculate energyWhere our body gets energy

What ways our body uses energy

Energy Review• Energy is the ability to do work

• Energy can be calculated by

• The units of Energy are Joules or calories

Q=cmΔT

How many calories does the average person need to take

in each day?

2 million!2 million!

Calorie vs. calorie?

Is it!!??

1 Calorie = 1,000 calories

(or 1 kilocalorie)

How do we measure energy?

What did we do in our Crash lab?

We measured the amount of heat the water in the can absorbed as the fuel burned.

Bomb Calorimeter

But the food industry determines how many calories food has using a…

How does it work?

*The food burns in the “steel bomb” and heat is released.

*The water absorbs the heat.

*We can measure the temperature rise in the water and calculate the amount of heat absorbed.

What are the advantages of using a Bomb Calorimeter over the can method?

• The water absorbs nearly all the heat – virtually none is lost to the surroundings.

• You have water that won’t evaporate during the experiment nor warm or cool from the surrounding air.

Reading Food

Labels

How many Calories do you need?

http://www.bmi-calculator.net/bmr-calculator/

… and type in your height, approximate weight, age, and gender.

That is your Basal Metabolic Rate (BMR).

That is your Basal Metabolic Rate (BMR).

Go to…

How are our Calories used?

What are some basic life functions that require Calories and how many

Calories do YOU need just to do that?

What are some basic life functions that require Calories and how many

Calories do YOU need just to do that?

What other ways do we use Calories?What other ways do we use Calories?

So where do we get our calories?

From our Food! (We can’t get it directly from the sun like

plants)

Carbohydrate = 4 Calories(sugars are a type of carbohydrate)

Fats = 9 CaloriesProtein = 4 Calories

Calorie conversion

Carbohydrate = 4 CaloriesFats = 9 CaloriesProtein = 4 Calories

25 X 4 = 100 Calories from carbohydrates

12g X 9 = 108 Calories from fat

4g X 4 = 16 Calories from protein

Total = 224 Calories

Why is our total more than the 220 reported on the label?

Let’s read the label and calculate!

Macromolecule Science Fair!

Task: Your task today is to develop an informational poster for kids, describing one of the following macromolecules:

•Carbohydrates•Proteins•Lipids/Fats

Your poster must answer the following questions…

1. What does the macromolecule look like? What elements are present?

2. What does the body use it for?3. How many Calories per gram are

there? (kcal/g)4. How much should be consumed daily?5. What are some of the different types?6. What types of food contain a lot of

your macromolecule?7. List three interesting facts.

Gallery Walk!

Use the note sheet provided to guide you through your

gallery walk. Be sure you understand what you are reading!

If not, ask the experts!

Use the note sheet provided to guide you through your

gallery walk. Be sure you understand what you are reading!

If not, ask the experts!