Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

NUTR 3210 > Energy Metabolism > Flashcards

Energy Metabolism Flashcards

1
Q

what is the cellular source of energy

A

ATP

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

what does ATP do/ where does it come from? `

A
  • sustains physical energy, anabolism, active transport

- supplied by the macronutrients in the diet

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

how many chemistry calories are in a food calorie

A

1000 chemistry calories = 1 food calorie

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

how many KJs are in 1 food calorie

A

1 food calorie = 4.18 KJ

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

describe positive energy balance

A
  • weight gain/ obesity
  • infertility
  • increased blood lipids
  • insulin resistance
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

describe negative energy balance

A

weight loss

  • infection
  • loss of performance
  • reduced bone mass
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

what did Antoine Lavoisier do?

A
  • compared heat produced by a genie pot with the production of co2
  • ice calorimeter (heat produced estimated by the amount of ice that melts
  • CO2 formed from the reaction between oxygen and organic matter
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

what did Justin Liebig recognize?

A

Justin Leigib recognized that protein, carbohydrates, and fats are oxidized by the body

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

what did max rubner do?

A

max rubner measured energy values of certain foods to determine caloric content

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

what is calorimetry

A

it is the measurement of heat production

- uses heat as an indicator of the amount of energy stored in the chemical bonds of food

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

what are the steps when carrying out bomb calorimetry

A
  1. dry and weight sample and place in enclosed chamber- with oxygen
  2. ignite the sample
  3. heat released is absorbed by the water and measured
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

what are the potential sources of error in terms of bomb calorimetry

A
  • overestimate energy (we dont digest like a bomb calorimeter)
  • doesn’t take into account energy needed for digestion/ absorption
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

what is the Atwater value for CHO

A

4 kcal/g

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

what is the Atwater value for fat

A

9 kcal/g

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

what is the Atwater value for protein

A

4kcal/g

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

what are Atwater values

A

physiological fuel values

- take into account incomplete digestion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

why does fat provide more kcal per gram vs CHO or protein

A

the chemical structure of CHO, fat, and protein indfluence the heat combustion for macronutrients

18
Q

describe the chemical structure of CHO

A

ratio of hydrogen to oxygen= 2:1

19
Q

describe the chemical structure of protein

A
  • has nitrogen, which contributes to gross energy

however, our bodies dont use nitrogen for energy

20
Q

describe the chemical structure of lipids

A
  • less oxidized than CHO and protein
  • ratio of hydrogen to oxygen I much greater than 2:1
  • lipids have lots of hydrogen atoms available for cleavage and oxidation for energy
21
Q

what does the bomb calorimeter measure

A

the bomb calorimeter measures gross energy of a compound

22
Q

what are the factors that affect heat combustion of fatty acids

A
  • unsaturation (the more double bonds, the less energy provided by that molecule)
  • chain length (the longer the chain, the more energy provided)
23
Q

what is the heat increment of feeding (HIF)

A
  • thermic effect of food
  • energy used for digestion, absorption, distribution, and storage of nutrients
  • is about 5-30% of daily energy usage
  • used to determine net energy
24
Q

what is net energy

A

net energy= metabolized energy - HIF

- supports basal metabolism, physical activity, growth, pregnancy, etc

25
Q

how much energy is partitioned towards HIF

A

5-30% of the metabolized energy is used for basic digestion mechanisms

26
Q

what are the 4 primary components to energy expenditure?

A
  1. basal metabolic rate (BMR)
  2. Thermic effect of food (HIF)
  3. physical activity energy expenditure (PAEE)
  4. thermoregulation (a minor contribution)
27
Q

what tissued are most reflective of the BMR

A

muscle and bone

28
Q

what is the equation used when calculating BMR

A

BMR= A * [M^0.75] kcal/day

  • A= metabolically active tissue (for humans, A=70)
  • M = body weight in Kg
29
Q

what is kleibers law

A

(0. 75)

- a constant used for all vertebrates, invertebrates, and unicellular organisms when calculating BMR

30
Q

what are the factors that can affect BMR

A
  • genetics
  • age
  • sex
  • tissue proportions
  • temperature
31
Q

how does genetics affect BMR

A

inheritance of a fast or slow metabolic rate

32
Q

how does exercise affect BMR

A

exercise changes body tissue proportions

muscle uses more energy than fat

33
Q

what does indirect calorimetry measure?

A

O2 intake, CO2 output

- energy- releasing reactions in the body depends on the use of oxygen

34
Q

what does direct calorimetry measure?

A

Heat output

- measures the heat a person generates (total heat loss)

35
Q

what is the issue with indirect calorimetry?

A

this method can not account for anaerobic processed (ie- production of lactic acid)

  • hyperventilation
  • masks are impractical
36
Q

what is the issue with direct calorimetry

A
  • expensive

- impractical

37
Q

compare direct vs indirect calorimetry

A

<1% difference

very comparable

38
Q

what is the respiratory quotient (RQ)

A

a ratio of metabolic gas exchange
provides information about:
- energy expenditure
- biological substrate being oxidized

39
Q

what is the equation used when calculating RQ (respiratory quotient)

A

RQ= (CO2 produced)/(O2 consumed)

40
Q

why do RQ values for macronutrients vary

A

differentiations in chemical composition mean that each macronutrient required a different amount of oxygen intake in relation to CO2 produced

ie- fats require almost three times as much oxygen (in comparison to carbs) to complete the digestion

NUTR 3210 (6 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions