Energy Production/Expenditure (2)

Question 1

implications of ATP being a limited currency

Answer 1

ATP needs to be constantly resynthesized
ATP levels only decrease in skeletal muscle under EXTREME exercise conditions
body stores 80-100g of ATP normally- enough to power 2-3 seconds of maximal exercise

Question 2

Why is phosphocreatine (PCr) the energy reservoir?

Answer 2

anaerobic splitting of phosphate from PCr= energy
cells store ~4-6x more PCr
PCr reaches its maximum energy yield in about 10s

Question 3

Anaerobic glycolysis

Answer 3

rapid
results in pyruvate to lactate formation
5% of energy from original glucose molecule

Question 4

Aerobic glycolysis

Answer 4

pyruvate to acetyle COa to citric acid cycle and electron transport of the remaining energy within glucose molecule (95%)

Question 5

Citric Acid Cycle

Answer 5

second stage of carb breakdown to produce CO2 and hydrogen atoms within mitochondria

Question 6

how many ATPs does the complete breakdown of glucose yield

Answer 6

34 ATPs

Question 7

how much ATP does fat catabolism yield

Answer 7

460 ATP molecules

Question 8

when does fat become the primary energy fuel for exercise and recovery

Answer 8

intense, long-duration exercise that depletes both blood glucose and muscle glycogen

Question 9

what is the most plentiful source of potential energy?

Answer 9

stored fat

Question 10

how does protein get used as energy

Answer 10

amino acids get converted- nitrogen removal

Question 11

what does protein catabolism require and why?

Answer 11

an increase in body’s water needs because it yields waste products that get eliminated in urine

Question 12

power generated by fat breakdown vs power generated by carb breakdown

Answer 12

power by fat breakdown is about half as much as carb breakdown (aerobic)

Question 13

can fatty acid substrate make up for a decrease in muscle glycogen even if it’s around in large amounts?

Answer 13

nahhh b

Question 14

where does fatty acid breakdown go?

Answer 14

accumulates in extracellular fluid and cannot enter the citric acid cycle

Question 15

how much ATP and PCr does each kg of skeletal muscle contain, respectively?

Answer 15

3-8mmol ATP

4-5x more PCr

Question 16

when does lactate acid accumulation occur?

Answer 16

50-55% of maximal capacity of aerobic metabolism in healthy, untrained persons
(at less than 50%, lactate accumulation=lactate disappearance)

Question 17

when does the blood lactate threshold occur?

Answer 17

when muscle cells can neither meet energy demands aerobically nor oxidize lactate at its rate of formation

Question 18

what is steady state aerobic metabolism?

Answer 18

a balance between energy required by working muscles and ATP production in aerobic reactions
there is no appreciable blood lactate acid accumulation

Question 19

what are two steady state aerobic metabolism limiting factors?

Answer 19

fluid loss and electrolyte depletion
maintaining adequate reserves of both liver glycogen and muscle glycogen for CNS function and exercise power, respectively

Question 20

what are two factors that help to explain athlete’s high steady-rate levels?

Answer 20

1. high capacity of the central circulation to deliver oxygen to working muscles
2. high capacity of the active muscles to use available oxygen

Question 21

what is the oxygen deficit?

Answer 21

difference between total oxygen consumed during exercise nd the total that would have been consumed had steady-state oxygen uptake been achieved at the start of exercise

Question 22

which individuals reach steady state first?

Answer 22

endurance-trained individuals

Question 23

what three adaptions increase an individual’s total capacity to generate ATP aerobically?

Answer 23

1. more rapid increase in muscle bioenergetics
2. more rapid increase in overall blood flow
3. disproportionately large regional blood flow to active muscle complemented by cellular adaptions

Question 24

when does VO2 max occur?

Answer 24

oxygen uptake plateaus or increases only slightly with additional increases in exercise intensity- range!!

Question 25

what does a high VO2 max require?

Answer 25

integrated and high-level responses of five diverse physiological support systems (pulm, hemoglobin, CO, peripheral BF, and aerobic metabolism)

Question 26

What is EPOC?

Answer 26

recovery oxygen consumption
EPOC= total recovery VO2 - total VO2 consumed at rest during the recovery
Restores the body to its pre-exercise condition

Question 27

intermittent physical activity

Answer 27

application of different work-to-rest intervals with supermaximal exercise to overload a specific energy transfer system

Question 28

Respiratory Quotient

Answer 28

carb, fat, and protein require different amounts of O2 for complete oxidation of each molecule’s carbon and hydrogen atoms to CO2 and H2O end-products

Question 29

RQ=

Answer 29

CO2 produced ÷ O2 consumed

Question 30

Carb RQ

Answer 30

1

Question 31

Fat RQ

Answer 31

.7

Question 32

Protein RQ

Answer 32

.82

Question 33

Respiratory Exchange rate (RER)

Answer 33

ratio of CO2 produced to O2 consumed when factors other than food combustion contribute to gas exchange

Question 34

what does RER indicate

Answer 34

that pulmonary exchange of O2 and CO2 no longer reflext only cellular oxidation of specific foods

Question 35

RER > 1 =

Answer 35

excess CO2 production in relation to O2 uptake