10. Metabolic Rate

Question 1

Metabolic Rate (MR)

Answer 1

rate at which chemical energy is expended by the body

expressed as kJ/min

Question 2

Metabolism provides energy for

Answer 2

1. Basal biochemical processes
2. Thermoregulation (heat produced)
3. External work (eg exercise)

Question 3

Increasing age

Answer 3

MR decreases

Question 4

Starvation

Answer 4

↓ sympathetic activity

↓ thyroid hormones

↓ BMR and MR

↓ insulin

↑ glucagon

Question 5

Pregnancy

Answer 5

MR ↑ in later stages

Fetus consumes mother’s energy

Mum can become insulin resistant

Metabolic shift towards fat metabolism in mum

Question 6

Hyperthyroidism

Answer 6

Increase MR

Question 7

Hypothryroidism

Answer 7

Decrease MR

Question 8

Fever, tumours, burns

Answer 8

Increase MR

Question 9

Ebb phase

Answer 9

MR ↓ early after trauma

insulin resistance

Conserve glucose for the brain

Thermoregulate around lower temperature

Question 10

Flow phase

Answer 10

Occurs within days of the injury

↑ MR

↓ appetite

Insulin resistance

Metabolic shift towards fat metabolism

Gluconeogenesis for glucose for CNS

muscle wastage as body breaks down protein for glucose

Give lipid drip – not glucose!

Question 11

Basal metabolic rates used for:

Answer 11

Breathing

Beating heart

Maintenance of cell membrane potentials

Digestion

Protein synthesis

Question 12

Conditions under which BMR is measured

Answer 12

1) Room temp (thermo-neutral environment)
2) Overnight fast
3) Physical activity

Question 13

Technique used to measure MR

Answer 13

Calorimetry

Question 14

RQ

Answer 14

CO2 produced: O2 consumed

Question 15

Measuring metabolic rate: Indirect calorimetry

Answer 15

Sample expired air

Calculate RQ

Look up in table amount of energy yielded per mole of O2 at that RQ (metabolising that fuel)

convert to MR

Question 16

MR

Answer 16

VO2 x energy liberated per mole of O2

Question 17

Is MR greater in women or men?

Answer 17

Women