WHAT DOES IT MEAN TO BE HEALTHY?

Nancy Dooley

Brainstorm and make a list of foods that give your body energy.

Think of different energy needs:working outtaking a test

playing a sport

Do now

Organisms maintain a dynamic

equilibrium that sustains life

Life is dependent upon availability of an energy source and raw materials that are used in the basic

enzyme-controlled biochemical processes of

living organisms.

Because organisms are continually

exposed to changes in their

external and internal

environments

they must continually monitor and

respond to these changes.

Responses to change can range in complexity from simple activation of a cell chemical process

to elaborate learned behavior

The result of these responses is called

homeostasis, a “dynamic equilibrium “or “steady state” which keeps the

internal environment within certain limits.

These mechanisms maintain the physical and chemical

aspects of the internal environment within narrow limits that are favorable for

cell activity.

Failure of these control

mechanisms can result in disease or even death.

Organisms have a diversity of homeostatic feedback mechanisms that detect

deviations from the normal state and corrective actions to return their systems to

the normal range

OUR UNIT GOAL: THIS WEEK

WHAT MAKES US HEALTHY? WHAT KEEPS US

HEALTHY? HOW DO OUR BODIES GET ENERGY?

WHAT MAKES US SICK? HOW DO OUR BODIES HELP US? HOW DO OUR BODIES

HURT US?

LET’S CREATE AN EXPERIMENT THAT ANSWERS OUR QUESTIONS

What foods give us the most energy? What type of food item: protein,

carbohydrate, fat? Give me an example of a protein?

Carbohydrate? Fat? Processed junk food?

Choose some food items from the baskets to experiment with.

How could we measure the energy supply that comes out of the food?

Let me explain a way we can try to do this.

WE ARE GOING TO SET THINGS ON FIRE AND COLLECT DATA WITH A DATA PROBE AND OUR COMPUTERWhat supplies do we need?

Let’s review safety procedures for dealing with fire?

Let’s get into our groups, collect supplies, task cards, lab books, lab guides

What challenges might we face with this experiment?

TECHNOLOGY

PredictionsPredictions

Why did you choose the foods you did and why do you think they give our body the most

energy?

FatProteinCarbohydrate

s

How does our body work to break these down? Does anyone remember

the word ENZYMES?

Anyone ever hear of the Food Pyramid?

Let’s analyze our data

How should we record our data? What might it tell us?

Think Think ThinkWhat else effects our energy? Which foods have the greatest

energy output?

Some of your questions

Can this experiment help us choose healthier foods?

Can we change food to make it healthier for us to eat? (follow up

Genetic Engineering)

LET’S ANALYZE OUR DATA COLLECTED FROM OUR

DATA PROBE

Marshmallow

Bread

Carrot

Meat

LET’S FIGURE THIS OUT

What have we found here?

Equations: • Heat calories = Mass of H2O (g) x

Change in Temperature of the

water (C) x 4.18 J/g C• Kilocalories = Heat calories (cal)

/ 1000 (cal/Kcal) • Energy yield = Kilocalories (Kcal)

/ Grams of food (g)

RESULTS FROM GROUP 1

Table 1 Measurements Sample 1 Sample 2 Sample 3 Sample 4Food used Marshmallow Bread Carrot MeatMass of empty can (g) 20000g 20000g 20000g 20000gMass of can plus water (g) 65000g 65000g 65000g 65000gMinimum temperature of water (°C) 20.8 C 22.2 C 23 C 22.6 CMaximum temperature of water (°C) 49.6 C 42.1 C 33.9 C 60.2 CInitial mass of food (g) 10000g 10000g 10000g 10000gFinal mass of food (g) 7500g 9000g 5000g 8000g

Table 2 Calculations Sample 1 Sample 2 Sample 3 Sample 4Mass of water (g) 45000 45000 45000 45000∆t of water (°C) 28.8 19.9 10.9 37.6∆mass of food (g) 2500 1000 5000 2000Energy gained by water (J) 5417280 J 3,743,190 J 490,500 J 1692000 JEnergy content of food (J/g) 2.166912 3.74319 0.410058 3.53628

PREDICTIONS: ARE THEY CORRECT?1. We set up our

experiment2. We burned stuff3. We measured stuff4. We wrote down stuff5. We compared stuff6. Now we talk about

stuff…

Living Environment: Lab 16