3.8 Gastrointestinal Physiology Energetics

Question 1

two general methods that nutrients energy is transferred to ATP?

Answer 1

anaerobic

aerobic

Question 2

anaerobic mechanisms

Answer 2

• useful for short term
• only small amounts of energy made
• LACTIC ACID production

Question 3

aerobic mechanisms

Answer 3

produce more ATP

*requires oxygen and more time

Question 4

define efficiency of cell energy extraction

Answer 4

= total work done / total energy expenditure = % of energy actually used to do work

Question 5

energy released per unit of ____ consumed

Answer 5

oxygen

Question 6

repiratory quotient is ____ produced per unit of oxygen consumed

Answer 6

CO2

Question 7

points of energetics is to determine?

Answer 7

main nutrient being metabolized by tissue

Question 8

define metabolic rate

Answer 8

energy consumed per unit of body surface area per unit of time
*effected by age, body temp, specific dynamic action of food, hormones and physical activity

Question 9

body temp is __% increase in metabolic rate per __degree F

Answer 9

6% per 1 degree

Question 10

what is specific dynamis action of food?

Answer 10

• diet induced thermogenesis
• energy required for the process of digesting and assimilating food after a meal
• protein is greatest increase in MR

Question 11

why does protein is greatest increase in metobolic rate?

Answer 11

takes more energy to digest and assimilate protein than CHO or fat (fat is least)

Question 12

thyroxine

Answer 12

hormone that is most important in regulating metabolic rate (T3 more than T4)

Question 13

do epi and nor stimulate metabolism?

Answer 13

yes

Question 14

what are the sex hormones that stimulate metabolism?

Answer 14

testosterone > estrogen

*MR greater in males generally do to their larger amounts of testosterone

Question 15

metabolic rate stongly affected by?

Answer 15

size of person and also by amount of physical movement

Question 16

when is minimal metabolic rate?

Answer 16

during sleep (~65 cal/hr in ave. size male)

Question 17

what is basal metabolic rate?

Answer 17

metabolic rate required for basic body functions at rest and awake

Question 18

what are the conditions required to measure BMR?

Answer 18

1) comfortable room temp (70-80F)
2) at rest for at lest one hour
3) fasted for at least 12 hours

Question 19

what is a direct measurement of basal metabolic rate?

Answer 19

direct calorimetry= measure heat given off with whole body calorimeter

Question 20

what is a indirect measurement of basal metabolic rate?

Answer 20

indirect calorimetry (easier)

• measure oxygen uptake
• since oxygen is not stored and since its consumption generally keeps pace with immediate needs of the body, the amount of O2 consumed per unit of time is proportionate to the energy used

Question 21

hypoerthyroidism

Answer 21

can inrease BMR to +100% of normal

Question 22

hypothyroidism

Answer 22

can decrease BMR to 50% of normal (still have epi, NE, and sex hormones keeping BMR up)