Final Flashcards
(106 cards)
The flow of energy in a biological system: the conversion of macronutrients into biologically usable forms of energy
Bioenergetics
The breakdown of large molecules into
smaller molecules, associated with the release of
energy
Catabolism
The synthesis of larger molecules from
smaller molecules; can be accomplished using the
energy released from catabolic reactions
Anabolism
Energy-releasing reactions that
are generally catabolic.
Exergonic reactions
Require energy and include
anabolic processes and the contraction of muscle.
Endergoinc reactions
The total of all the catabolic or exergonic
and anabolic or endergonic reactions in a biological
system.
Metabolism
Allows the transfer of
energy from exergonic to endergonic reactions.
Adenosis triphosphate (ATP)
Three basic energy systems exist in muscle
cells to replenish ATP:
Phosphagen, glycolysis, oxidative system
short-term, high-intensity activities (e.g.,
resistance training and sprinting)
Phosphagen system
active at the start of all exercise regardless of
intensity
• Creatine kinase catalyzes the synthesis of ATP
from CP and ADP
Phosphagen system
The breakdown of
carbohydrates—either
glycogen stored in the
muscle or glucose
delivered in the blood—
to resynthesize AT
Glycolysis
The end result of glycolysis (pyruvate) may
proceed in one of two directions:
- Pyruvate can be converted to lactate
• Anaerobic glycolysis, faster, shorter duration - Pyruvate can be shuttled into the mitochondria
• Aerobic glycolysis (Krebs cycle), slower, longer duration
Marker of anaerobic threshold
Lactate threshold
The exercise intensity or relative intensity at which blood lactate begins
an abrupt increase above the baseline concentration
LACTATE THRESHOLD in untrained individuals
50% to 60% VO2max
Lactate threshold in aerobically trained athletes
70-80%
0-6 second extremely high
Phosphagen
6-30sec very high
Phosphagen and glycolysis
Greater than 3 min, low
Oxidative
2-3 min, moderate
Fast glycolysis and oxidative
Oxidative system=
Aerobic
Primary source of ATP at
rest and during low-
intensity activities
Oxidative (Aerobic)
Primarily uses
carbohydrates and fats
Oxidative (aerobic system)
Creatine phosphate can decrease markedly
(50-70%) during the
first stage (5-30 seconds) of high-
intensity exercise and can be almost eliminated as a
result of very intense exercise to exhaustion