Metabolism, Nutrition, and Energy Flashcards
How many calories in a Calorie, how many in 1 Kcal?
1000 calories in a Calorie and 4.185 calories in a Kcal
What is catabolism?
Degradative process, some will yield useful energy, oxidative
What is anabolism?
Bio synthetic process that makes cellular materials, require energy, reductive
Exergonic Properties
Downhill reactions, with available energy; reactants have high energy while products have low energy; delta G is negative (favorable); spontaneous reaction proceeds forward
Endergonic Properties
Uphill reactions; require energy; reactants have low energy and products have high energy; Delta G is positive (unfavorable); spontaneous reaction proceeds backward
How to drive unfavorable reaction?
By coupling them-hydrolysis of ATP
Relative heat value of fat?
9 cal/g
Relative heat value of carb?
4 cal/g
Relative heat value of protein?
4 cal/g vs 5 cal/g in bomb calorimeter
Relative heat value for ethanol?
7 cal/g
Why do proteins yield less energy in body than in bomb calorimeter?
Some protein remains unavailable as urea
What is respiratory quotient?
RQ= CO2produced/ O2 utilized
RQ for carb = ?
1.0
RQ for fat= ?
0.7
RQ for protein= ?
0.8
An individual at rest has an RQ of ?
.08
RQ for individual performing exercise=?
1.0
RQ of arm at rest=?; why?
0.7 because resting muscle utilizes fat instead of carb
RQ for brain=?;why?
1.0 because main energy supply is glucose
How to calculate basal metabolic rate (BMR)
Weight in kg x 24 hrs, add 1/3 to account for normal level of physical activity
How to calculate BMR in KJ?
Weight x 100 kJ
BMR differences
Male>Female Younger>older Tall>short Lactating> pregnant >not pregnant and not lactating Leaner tissue>fat Fever can raise BMR by 14%/ degree Celsius Fasting/starving decrease BMR More thyroxine >
What is the principal reserve for long term food deprivation?
Fat mostly as TAGs
