5.6 Flashcards
Metabolism refers to
Chemical reactions in the body
1 calorie= ___ J
4.2 Joules
How do we measure the amount of energy food provides?
Calorimeter- burns food
energy content of carbohydrates
17.2 kJ/gram
energy content of proteins
17.2 kJ/gram
respiratory quotient (RQ) is the ratio:
RQ = CO2 eliminated / O2 consumed
for each nutrient the metabolism is different
energy content of fat
39 KJ/gram
RQ for carbohydrates
1
RQ for proteins
0.82
RQ for fat
0.7
How can we measure TEE?
measuring a personws heat production (=rate of metabolism)
TEE=
heat production + external work
What is the indirect method of measuring TEE?
we measure oxygen consumption
Define BMR
minimal energy expenditure required to exist
awake, without physical activity
TEE=
BMR + DIT + EE in physcial activity
Diet Induced Thermogenesis
How do we measure BMR?
- usually in the morning
- no physical activity
- 20 C
- no food
- no stress
- no drugs
Normal BMR values
Men= 7,000 KJ/day Women= 6,000 KJ/day
BMR is influenced by
- body size
- sex
- age
- temparture
- climate
- pregnancy
- some hormones
- drugs, stress, injuries
BMR is how much of TEE?
usually 50-70%
DIT is how much of TEE?
10-15%
EE in physical activity is how much of TEE?
15-30%
Brown adipose structure?
less fat
a lot of mitochondria
What is the special feature of brown adipocyte?
their mitochondria contains Uncouplin Protein (UCP1)
UCP1 effect?
allows H+ to flow from intermembrane space to matrix
leading to less ATP synthesis and more heat production
