Lesson 2- Defining and Measuring Energy

Question 1

What is Energy?

Answer 1

Ability to do work (mehcnaical energy)
- Other types of energy include chemial and heat energy)

Question 2

What is energy expenditure?

Answer 2

energy/time

Question 3

What type of energy am I referring when talking about calorie?

Answer 3

Heat energy

Question 4

What is a calorie?

Answer 4

Energy needed to raise 1 g of water by 1degree celsius

Question 5

Is c or C expressed on food labels?

Answer 5

Calorie is a kcal and calorie is a single calorie

Question 6

What is a Joule?

Answer 6

Energy required to move a mass of 1 g at a velocity of 1 m/s

Question 7

What is 1 cal equal to in J?

Answer 7

1 cal = 4.186 J

Question 8

What type of energy does a J measure?

Answer 8

Chemical Energy

Question 9

What type of energy does a calorie measure?

Answer 9

heat energy

Question 10

What is the first law of Conservation of Energy?

Answer 10

In a closed system, energy cannot be created or destroyed, it is only transformed from one type to another

Question 11

Where does the 20% of energy go to in humans? and the 80%?

Answer 11

20% –> goes for movement and work
80% –> goes to maintaing homeostasis

Question 12

How does ATP provide us with energy?

Answer 12

We get energy off of it through a very rapid one step chemical reaction where a phosphate group is removed

Question 13

What catalyst is responsible for removing the phosphate group?

Answer 13

It is the enzyme called ATPase

Question 14

Is ATP relevant for the relxation of the muscle and the firce production?

Answer 14

YES, for both

Question 15

What are the 3 systems for ATP use?

Answer 15

-Creatine phosphate
-Anaerobic glycolysis
-Oxidative phosphorylation

Question 16

What is the unit of measure for energy?

Answer 16

It is Joules (J)

Question 17

What is a bomb calorimeter?

Answer 17

its a device that determines energy by the amount of heat produced.

Question 18

How is a bomb calorimeter used?

Answer 18

The “bomb” is a
metal container in which the food sample is burned in a
pressurized, pure oxygen atmosphere. It is constructed
to withstand high temperature and pressure, and it is
surrounded by a water bath that is insulated from outside temperature changes. As the food sample burns,
the temperature change in the surrounding water bath
is recorded with a sensitive thermometer to determine
the thermal energy of the food.

Question 19

What does direct calorimetry indicate and indirect calorimetry indicate?

Answer 19

Direct calorimetry - heat energy measured through change in temperature
Indirect calorimetry - looks at oxygen consumpotion and CO2 production to energy expenditure and heat production

Question 20

What are the most commonsly used systems ?

Answer 20

Open cicuit - in which the subject breathes in ambient room air and is not confined to breathing the air within a sealed environment.

Question 21

What are the conditions that need to be met for meauring the REE (resting energy expenditure)? (8 conditions)

Answer 21

• Resting supine position >30 mins
• No alchol for >48hrs
• Fasting >12hrs
• Nicotine >1hr
• Caffeine >4 hrs
• Exercise >24-48hrs
• Normal acid-base balance
• Quiet, dark, thermoregulated room

Question 22

What is RER?

Answer 22

Respiratory exchange ratio

Question 23

What is the formula for RER?

Answer 23

RER = VCO2/VO2

Question 24

When would you have an RER > 1.0?

Answer 24

• Hyperventilating
  -Lipogenesis

Question 25

What is the RER for proteins, carbs and lipids?

Answer 25

Carbs RER: 1.0 Lipids RER: 0.7 Protein 0.8

Question 26

Frequently used methods for estimating energy intake? (3)

Answer 26

1. Food diary 2. Food frequency questionnaire 3. 24 hr recall

Question 27

Self reported food intake (4)

Answer 27

1- need accruate recordings issues with this: - portion sizes must be estimated correctly -food intale is typically underestimated (12-16% up to 20%) erors in data entry can occur

Question 28

How much % is the energy expenditure of a sedentary person?

Answer 28

70%

Question 29

Thermic effect of food accounts for how many %?

Answer 29

10%

Question 30

How mcuh does physical activity account for?

Answer 30

20%

Question 31

Which of these is mostly readily influenced in terms of energy expenditure?

Answer 31

Physical Activity

Question 32

Factors affecting resting metabolic rate? (Influence not under voluntary control)

Answer 32

 Gender  Genetics  Age  Body size (Height)  Thyroid hormones

Question 33

Factors affecting resting metabolic rate? (Substantial influence under some voluntary control)

Answer 33

 Starvation  Amount of fat free tissue

Question 34

Factors affecting resting metabolic rate? (Subtle or temporary influence, under voluntary control )

Answer 34

 Exercise  Environment temperature  Ascending to high altitude  Caffeine intake

Question 35

What are the activity factors?

Answer 35

-Sedentary (little to no exercise): 1.2 -Lightly active (1-3 days/week): 2.375 -Moderately active (3-5 days/week): 1.55 -Very active (6-7 days/week): 1.725 -Extra active (physical job 2x training): 1.9

Question 36

What are 2 factors that can decrease the RMR? (resting metabolic rate)

Answer 36

1. Starvation 2. Age

Question 37

What is the greatest influences on RMR ?

Answer 37

amount of body mass, specifically the free fat mass