ch3 bioenergetics of exercise and training Flashcards
bioenergetics def
the flow of energy in a biological system
bioenergetics is primarily concerned with…
the conversion of carbohydrate, protein, and fats into biologically usable forms of energy
the breakdown of large molecules into smaller molecules associated with the release of energy is called…
catabolism
the synthesis of larger molecules from smaller molecules can be accomplished using using energy from…
catabolic reactions
they sythesis of larger molecules from smaller molecules is called…
anabolism
exergonic reactions are
energy releasing reactions and are generally catabolic
endergonic reactions require energy and include…
anabolic processes and muscle contraction
metabolism is the…
total of all the catabolic /exergonic and anabolic / endergonic reactions in a biological system
energy derived from catabolic / exergonic reactions is used to…
drive anabolic / endergonic reactions through an intermediary molecule, adenosine triphosphate (ATP)
ATP allows the transfer of energy from ….
exergonic to endergonic reactions
ATP is composed of…
adenosine
3 phosphate groups
adenosine is the combenation of…
adenine (nitrogen containing base)
ribose (five carbon sugar)
the breakdown of one molecule of ATP to yield energy is known as…
hydrolysis (because it requires one molecule of water)
myosin ATPase is the
enzyme that catalyzes ATP hydrolysis for crossbridge recycling
calcium ATPase is the enzyme that
catalyzes ATP hydrolysis for pumping calcium into the sarcoplasmic reticulum
the energy released primarily from ATP and secondarily from ADP results in…
biological work
ATP is classified as a …
high energy molecule
muscle cells store a —– amount of ATP
limited
what are the three basic energy systems to replenish ATP?
phosphagen system
glycolysis
oxidative system
anaerobic processes…
do not require the presence of oxygen
aerobic processes require the presence of
oxygen
the phosphagen and glycolytic systems are …
anaerobic mechanisms
phosphagen and glycolysis occure in
the sarcoplasm of a muscle cell
the Krebs cycle, electron transport, and the rest of the oxidative system occur in
the mitochondria of muscle cells
of the three macronutrients, only carbohydrates can be …
metabolized for energy without the direct involvement of oxygen
carbohydrate is critical during what kind of metabolism?
anaerobic
all three energy systems are active…
at any given time
the magnitude of contribution of each energy system to overall work performance is primarily and secondarily dependent on…
primarily dependent on INTENSITY OF ACTIVITY and secondarily dependent on THE DURATION OF THE ACTIVITY
the phosphagen system provides ATP primarily for…
short term, high intensity activities
- resistance training
- sprinting
the phosphagen system is highly active at the start of…
all exercise regardless of intensity
the phosphagen system relies on the hydrolysis of ATP and the breakdown of
creatine phosphate
creatine phosphate is a
high energy molecule
another name for creatine phosphate (CP)
phosphocreatine (PCr)
the enzyme that catalyzes the synthesis of ATP from CP and ADP
creatine kinase
creatine phospate supplies a ——that combines with ADP to replenish ATP
phosphate group
creatine phosphate is stored in —- amounts, so cannot be the primary —
small
energy source for continuous, long duration activities
the body stores how much ATP at any given time?
80-100 g (about 3 ounces)
ATP stores cannot be completely depleated due to
the necessity for basic cellular function
under normal circumstances, skeletal muscle concentrations of CP are —–higher than ATP concentrations
4-6 x
type 2 muscle fibers contain a higher concentration of —-than type 1
creatine phosphate (CP)
adenylate kinase, myokinase is an
enzyme that, like creatine phosphate, can rapidly replenish ATP
—-> ATP + AMP
AMP, a product of adenylate kinase, is important because
it is a powerful stimulant of glycolysis
the reactions of the phosphagen system are largely controlled by…
the law of mass action (the mass action effect)
what is the law of mass action (the mass action effect)?
the concentrations of reactants or products (or both) in solution will drive the direction of the reactions.
how does the law of mass action affect the phosphagen system?
as ATP is hydrolyzed to yield energy, there is a transient increase in ADP and P concentrations in the sarcolema…
this will increase the rate of the creatine kinase and adenylate kinase reaction to replenish the ATP supply
glycolysis is the…
breakdown of carbohydrates - either glycogen stored in teh muscle or glucose delivered in the blood - to resynthesize ATP
the process of glycolysis involves ——, so is not as rapid as the single-step phosphagen system
multiple enzyme reactions
glycolysis vs phosphagen system ability to produce ATP
glycolysis has a much higher capacity to produce ATP due to the large availability of glycogen and glucose as compared to CP
glycolysis occurs in the
sarcoplasm
—–is the end result of glycolysis
pyruvate
pyruvate may proceed in one of two directions…
1) pyruvate can be converted to lactate in the sarcoplasm
2) pyruvate can be shuttled into the mitochondria
