GI 8 Flashcards
energy input
diet
energy output
heat and work
one kilocalorie
the amount of heat needed to raised the temperature of 1L of water by 1*C.
How does a bomb calorimeter work?
Heat released from burned food is measured
Are bomb calorimeters over estimates or under?
over because we do not completely digest and absorb most foods
Which is more accurate: direct or indirect calorimetry?
direct
basal metabolic rate (BMR)
an individuals lowest metabolic rate
How is BMR usually measures?
as resting metabolic rate (RMR)
Factors that affect overall metabolic rate?
- age and sex
- amount of lean muscle mass
- activity level
- diet
- hormones
- genetics
All chemical reactions in the body fall into which 3 categories?
- extract energy from nutrients
- use energy for work
- store excess energy
Fed state is mainly…
anabolic
Skeletal muscle during fed state
- takes up glucose for energy and stores it as glycogen (70% of body storage)
- proteins stored for natural turnover
Liver during fed state
- convert glucose to glycogen (24% of body storage) and to fatty acids
- protein used for synthesis and converted to kept acids
Adipocytes in the fed state
- take up dietary triglycerides from chylomicrons
- excess glucose converted to triglycerides
- stores triglycerides synthesized in liver
Glycogen and protein storage ________, fat storage _________.
limited, unlimited
Glycogen can sustain quiet activity for ______, proteins ___________, and fats for ___________
few hours, potentially long periods of time, approximately two months
Why is maintaining glucose levels important for nervous system function?
most cells utilize fatty acids to spare glucose for the CNS
skeletal muscle during fasted state
- can convert glycogen to glucose-6-P
- forms pyruvate and lactate
Liver during fasted state
- glycogen can be converted to glucose
- produce new glucose from pyruvate, lactate, glycerol and certain amino acids
- converts fatty acids to ketone bodies
adipocytes during fasted state
-lypolysis occurs; fatty acids and glycerol enter bloodstream to be used as energy
fasted state promotes…
catabolism
Fed state summary
- insulin secretion
- glucose primarily used by most cells for energy
- glycogenesis
- lipogenesis
- AA uptake and protein synthesis
fasted state summary
- glucagon secretion
- fatty acids used by most cells for energy
- glycogenolysis
- lipolysis
- gluconeogenesis
- ketogenesis
- protein degradation
