Chapter 3-Bioenergetics Flashcards Preview

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Flashcards in Chapter 3-Bioenergetics Deck (26)
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1
Q

Catabolism

anabolism

exergonic reactions

endergonic reactions

A

breakdown of larger molecules

building up of molecules

energy releasing reactions

require energy

2
Q

metabolism

A

total of all the catabolic and anabolic reactions in a biological system

3
Q

hydrolysis

A

breakdown of 1 molecule of ATP to yield energy

requires one molecule of water

4
Q

anaerobic

A

phosphagen and glycolytic systems do not require oxygen and occur in the sarcoplasm of the cell

only carbs can be metabolized into energy without the direct involvement of oxygen

5
Q

aerobic

A

krebs cycle, electron transport, and the rest of the oxidative system require oxygen and occur in the mitochondria of the cells

6
Q

phosphagen system

A

short-term, high intensity activities
highly active at the start of exercise
relies on hydrolysis and breakdown of creatine phosphate
limited by the small storage of CP

7
Q

law of mass action

A

the concentrations of reactants or products in solution will drive the direction of the reactions

8
Q

glycolysis

A

breakdown of either glycogen stores in muscle or glucose from blood to resynthesize ATP
not as rapid, but greater capacity due to greater supply of carbohydrates

9
Q

pyruvate

A

end result of glycolysis

can be converted to lactate which results in faster resynthesis of ATP

can be shuttled to mitochondria to undergo the Krebs cycle with a shorter resynthesis rate due to greater number of reactions but can occur for longer duration

10
Q

metabolic acidosis

A

process of an exercise-induced decrease in pH

may be responsible for the peripheral fatigue that occurs during exercise

11
Q

lactate accumulation

A

normal range is 0.5 to 2.2 mmol/L at rest
increases with exercise intensity

maximal rate of production is twice as much for Type II (0.5 mmol/g/s) compared to Type 1 (0.25 mmol/g/s)

severe fatigue may occur at blood concentrations between 20-25 mmol/L

influenced by exercise intensity, muscle fiber type, exercise duration, state of training and initial glycogen levels

12
Q

ATP yield

A

substrate-level phosphorylation during glycolysis yields 4 ATP

when it begins with blood glucose, 2 ATP are used, 4 are resynthesized for net gain of 2

when it begins with muscle glycogen, 1 ATP is used, 4 are resynthesized for net yield of 3 ATP

13
Q

Allosteric regulation

allosteric inhibition

allosteric activation

A

end product of a reaction feeds back to regulate the turnover rate of key enzymes in the metabolic pathways

an end product binds to the regulatory enzyme and decreases its turnover rate and slows product formation

an activator binds with the enzyme and increases its turnover rate

14
Q

regulatory enzymes in glycolysis

A

hexokinase, PFK and pyruvate kinase

15
Q

Lactate threshold

A

exercise intensity at which blood lactate begins an abrupt increase above the baseline concentration

typically begins at 50-60% of maximal oxygen uptake in untrained individuals and 70-80% in aerobically trained athletes

16
Q

OBLA

A

onset of blood lactate accumulation
second increase in the rate of lactate accumulation noted at higher relative intensities
occurs when the concentration of blood lactate reaches 4 mmol/L

17
Q

oxidative system

A

primary source of ATP at rest and during low-intensity activities
primarily uses carbs and fats as substrates
at rest, 70% of ATP is from fat and 30% from carbs
as intensity increase, these ratios change
during high-intensity almost 100% of energy comes from carbs

18
Q

oxidative phosphorylation

A

glycolysis and the Krebs cycle

40 total, but uses 2 ATP for a net gain of 38 ATP

19
Q

phosphagen

A

concentrations are more rapidly depleted during high-intensity anaerobic exercise
resting concentrations may be increased with training
primary limiting factor during high intensity exercise

20
Q

glycogen

A

300-400g are stored in muscle, 70-100g in liver
training can increase resting levels

repletion of muscle glycogen during recovery is related to ingestion
optimal levels are 0.7 to 3.0 g carbs per kg body weight every 2 hrs after exercise

21
Q

Interval training

A

method that emphasizes bioenergetic adaptations for a more efficient energy transfer within the metabolic pathways by using predetermined intervals of exercise and rest

allow for more training at higher intensities

22
Q

which substance can be metabolized anaerobically

A

glucose

23
Q

the reaction that is the primary cause of metabolic acidosis

A

breakdown of ATP releasing P and H

24
Q

which energy system produces ATP at the quickest rate

A

phosphagen

25
Q

how many net ATP are produced via the oxidative energy system from the metabolism of 1 glucose molecule

A

38

26
Q

which energy substrate cannot be depleted during extreme exercise intensities/durations

A

ATP