energy metabolism

Question 1

metabolism

Answer 1

the sum total of all chemical reactions occurring in an organism; the conversion of chemical energy into heat

Question 2

2nd law of thermodynamics

Answer 2

in a closed system, the universe is always moving towards disorder however, animals are an open system

Question 3

anabolic pathway

Answer 3

assembling of substances into complex molecules, requires energy

Question 4

catabolic pathway

Answer 4

the breakdown of energy rich complex molecules into simpler ones, energy is released or stored as ATP or glucose

Question 5

chemical energy

Answer 5

a form of potential energy, needed for atom reconfiguration

Question 6

electrical energy

Answer 6

a form of potential energy in the charge speculation of molecules

Question 7

heat

Answer 7

a form of kinetic energy that is formed by the random motion of all molecules; a degraded waste product in animals

Question 8

mechanical energy

Answer 8

a form kinetic energy that is the energy of organized motion

Question 9

work

Answer 9

a transfer of energy from one source to another

Question 10

physiological work

Answer 10

a process carried out by organisms that increases order in the internal or external environment such as the breakdown of molecules or body movement, can only be performed by high grade energy

Question 11

high grade energy

Answer 11

can perform physiological work; chemical, mechanical, electrical

Question 12

low grade energy

Answer 12

cannot perform physiological work; heat or other degraded energy form converting high to low

Question 13

ingested energy

Answer 13

energy found in the chemical bonds of consumed food

Question 14

fecal energy

Answer 14

energy from food that is unable to be digested

Question 15

absorbed energy

Answer 15

energy from food that is assimilated into the body and can be used; most of this is ultimately degrade to and released as heat

Question 16

3 routes of absorbed energy

Answer 16

biosynthesis, maintenance, and external work; all result in some heat production as a result of inefficiency

Question 17

biosynthesis

Answer 17

synthesis of body proteins and lipids; results in the accumulation of chemical energy in body tissues and is important for fat storage

Question 18

maintenance

Answer 18

maintain the integrity of the organism as a whole; most expensive energy process; primarily internal work such as circulation respiration and gut motility

Question 19

external work

Answer 19

mechanical work done outside the body such as eating and mating

Question 20

is energy recycled

Answer 20

no, and this explains why animals are constantly consuming throughout their lives

Question 21

metabolic rate

Answer 21

expressed as heat energy released per unit time or the rate of heat production; determines how much food an animal needs

Question 22

direct calorimetry

Answer 22

method of measuring metabolism that involves the measurement of energy released as heat over a given time

Question 23

indirect calorimetry

Answer 23

method of measuring metabolism that involves measuring metabolism from food intake and waste production

Question 24

respirometry

Answer 24

form of indirect calorimetry involving the rate of gas exchange with the environment

Question 25

material balance

Answer 25

form of indirect calorimetry that measures the chemical energy that enters and leaves the body

Question 26

radioisotopes

Answer 26

method of measuring metabolism that involves injecting isotopes of O2 and H into an organism, then measuring the loss of body water with respect to the loss of O2; must be measured in 24hr increments

Question 27

thermoconductivity

Answer 27

the ability to conduct heat

Question 28

summit metabolic rate SMR

Answer 28

coldest temperature at which an organism can maintain its temperature without reaching hypothermia

Question 29

respiratory ratios

Answer 29

respiratory quotient=(CO2 eliminated per unit time/ O2 consumed per unit time);RQ=1.0 for carbs, 0.71 for lipids, 0.83 for proteins; if the RQ is between any of these values we cannot determine what food is being used

Question 30

factors affecting metabolic rate

Answer 30

age, gender, diet, hormones, physical activity level, and amount of lean muscle

Question 31

Specific dynamic action SDA

Answer 31

the spike in metabolic rate that occurs immediately after a meal

Question 32

absorptive state (fed)

Answer 32

ingested nutrients enter the blood, some are used to supply needs of the body in the net synthesis of proteins, glycogen, and fat

Question 33

post absorptive state (unfed)

Answer 33

the digestive tract is empty and the available pool of nutrients in the blood decreases, there is a net degradation of proteins, glycogen, and fat

Question 34

basal metabolic rate BMR

Answer 34

measured in thermal neutral zone, while fasting and resting, and should be at the lowest point of the circadian and circannual rhythms; ultimate resting rate (used in homeotherms)

Question 35

standard metabolic rate SMR

Answer 35

must be measured at a certain temperature while fasting and resting (used in poikilotherms)

Question 36

BMR + SMR

Answer 36

both are a stable rate of energy metabolism under conditions of minimum environmental and physiological stress and after fasting

Question 37

temperatures affect on metabolism

Answer 37

temperature has a Q10 affect meaning that for every 10 degree change in temperature there is a 2-3x change in enzymatic activity and metabolic rate

Question 38

maximum metabolic rate MMR

Answer 38

exercise induced metabolic rate, approximately 10x BMR or SMR

Question 39

locomotion

Answer 39

the amount of energy required to move a unit of mass a unit of distance; small animals use more energy to achieve a given velocity than larger animals

Question 40

what is the most energy dense substrate

Answer 40

fat with at least 2x as much energy as proteins and carbs

Question 41

energy absorbed efficeincy

Answer 41

absorbed energy/ingested energy

Question 42

gross growth efficiency

Answer 42

chemical bond energy growth/ingested energy

Question 43

net growth efficiency

Answer 43

chemical bond energy added/absorbed energy; declines with age