NST10 - Lect4 energy

NST10 - Lect4 energy - MASS X VELOCITY = CALOR 1 The Law of...

Info iconThis preview shows pages 1–4. Sign up to view the full content.

View Full Document Right Arrow Icon
1 MASS X VELOCITY = CALOR
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
2 The Law of Constant Heat Sums -Hess (1840) The total amount of heat produced or consumed when a chemical system changes from an initial state to a final state is independent of the way in which this change is brought about. Can’t get something from nothing Energy Balance = Energy In + Energy Out (the food you eat) (expenditures) Positive Energy Balance: you eat more energy than you use -- gain weight Negative Energy Balance: you eat less energy than you use -- lose weight What we eat How we use energy
Background image of page 2
3 Estimating Energy (Kcal) Content of Food using a Bomb Calorimeter Direct Calorimetry 1. Burn food. 2. Measure heat given off. Does NOT tell how efficiently our bodies would use a food. We estimate the energy used for Basal Metabolism by measuring BASAL METALBOLIC RATE Other ways of measuring BMR are: a) Indirect calorimetry: the amount of oxygen consumed and carbon dioxide expelled. b) stable isotopes methods Why not direct calorimetry?
Background image of page 3

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Image of page 4
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 10/12/2008 for the course NUTRI SCI 10 taught by Professor Amy during the Fall '08 term at Berkeley.

Page1 / 9

NST10 - Lect4 energy - MASS X VELOCITY = CALOR 1 The Law of...

This preview shows document pages 1 - 4. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online