Unit 3 Flashcards

1
Q

how is energy defined

A

the capacity to do work or to preform an activity (any physiological process)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

what is a calorie (cal)

A

measure of heat that is used to express the energy content of food

kcal = 1000 calories = 1 Calorie = 1 cal
1 kcal = 4.18 KJ

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

what is a positive energy balance

A
  • energy IN > energy out
  • growth, pregnancy
  • weight gain/obesity
  • cardiovascular disease
  • insulin resistance
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

what is a negative energy balance

A
  • energy in < energy OUT
  • weight loss - over long time –> starvation
  • infection
  • fever
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

what is bomb calorimetry

A
  • measures heat produced when a food sample is combusted in a high O2 environment
  • works on the principle of direct calorimetry - food is burned completely and heat liberated measured
  • dry + weigh sample & place in enclosed chamber w O2
  • water surrounds chamber, sample ignited
  • heat released absorbed by water & measured
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

what is heat of combustion

A

gross energy (GE) - i.e. max amount of energy in sample

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

what is calorimetry

A
  • measures heat production, allows for estimation of potential energy that was present in food
  • measures heat released when foods are burned - provides a direct measure of amount of energy stored in chemical bonds of foods
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Describe energy partitioning

A
  • Gross energy (GE) - total food energy (bomb calorimeter)
  • energy is lost to feces
  • digestible energy (DE) - absorbed food energy
  • energy lost to gases (usually ignored in calculation)
  • energy lost in urine (protein - N in form of urea)
  • metabolizable energy (ME) - useable energy for body - feed directly into metabolic pathways -> ATP
  • energy list to HIF
  • net energy (NE) - basal metabolism activity, growth, lactation, pregnancy
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

what are Atwater’s physiological fuel values?

A
  • measure ME
  • fat: 9
  • protein: 4
  • CHO: 4
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What is HIF

A

heat increment of feeding

  • aka “thermic effect of food”
  • energy expended in digestion, absorption, distribution, and storage of dietary nutrients
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

what is NE?

A

net energy

- NE = ME - HIF

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

what are the three components of total energy expenditure (other than HIF)

A
  • BMR
  • physical activity energy expenditure (PAEE)
  • thermoregulation (sweating, shivering)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

what is Kiebler’s law?

A

metabolic rate (BMR of animal) proportionate to mass^0.75

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What factors affect BMR?

A
  • genetics
  • age
  • gender
  • exercise
  • ambient temperatures
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Describe direct calorimetry

A
  • energy expenditure can be measured by body heat production
  • measures heat a person generates
  • need to measure sensible heat loss & insensible losses
  • very expensive
  • impractical
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Describe indirect calorimetry

A
  • all energy releasing rxns in the body depend on the utilization of O2 & the production of CO2
17
Q

what is RQ?

A

respiratory quotient - also called RER respiratory exchange ratio

  • provides info about energy expenditure & biological substrates being oxidized for energy expenditure
  • RQ = CO2 produced / O2 consumed