Lab #9 Exercise Physiology Flashcards
Define aerobic metabolism
The process where oxygen is used to make energy from glucose
Define anaerobic metabolism
The process that makes glucose without oxygen’s presence.
Give an example of aerobic exercise and explain the primary source(s) of energy.
An example is running, which is an endurance exercise. The primary energy source will be fat. Fat breakdown yielding ATP is lipolysis. The rate of lipolysis is a limiting factor for acquiring ATP. As LIPOLYSIS incorporates overall muscle energy there will be a decrease as contraction INTENSITY increases. In the presence of glycogen DEPLETION, the rate of lipolysis will not be sufficient to reach the exercise’s demand. Depletion leaves few glycogen stores ready for resting muscle activity. Decreasing intensity will spare glycogen to avoid depletion.
What is the source of all muscle contractions?
ATP
When is energy released?
When it’s broken into ADP + Pi
What does ADP + Pi stand for?
adenosine diphosphate and a phosphate group
What is the limiting factor of skeletal muscles?
the ability to maintain the availability of ATP for muscle contraction
ATP is stored in large amounts in skeletal muscles (T/F)
( F ) ATP is not stored in large amounts in skeletal muscles
Where do viable sources of ATP come from?
anaerobic and aerobic means
anaerobic
does not require O2
aerobic
requires oxygen
What does the primary energy source for a given activity primarily DEPEND ON?
the INTENSITY of muscle contractions
The 2 main anaerobic sources of ATP
1) phosphocreatine (PCr)
2) anaerobic glycolysis
What are intramuscular PCr stores used for?
rapid high-intensity contractions
Con of intramuscular PCr stores.
are depleted in 8-10 seconds AND take several minutes to replenish
100 m sprint is an example of what?
PCr which provides the majority of energy
Pro of PCr stores.
ability to perform repeated bouts of near-maximal energy
What is anaerobic glycolysis?
breakdown of glucose (glycolysis) –> pyruvate
Oxygen’s effect on pyruvate.
in the ABSENCE of oxygen, pyruvate is CONVERTED to lactic acid
In muscle fibers, ___ is made available through the breakdown of muscle ___ stores.
glucose; glycogen
Anaerobic glycolysis is limited to the availability of what? aka what is the limiting factor
the accumulation of LACTIC ACID and other metabolites
Anaerobic:
Pro of anaerobic glycolysis?
ability to perform high-intensity exercise w/ duration of 1-2 minutes
Example of anaerobic glycolysis.
400 m swimmer
800 m race
What is aerobic glycolysis? (simple)
occurs when oxygen is available to breakdown pyruvate
Breakdown of pyruvate yields what?
ATP through chemical reactions that occur in the Krebs cycle & ETC
What is the similarity between anaerobic and aerobic metabolism?
glucose can be obtained from stored glycogen
Glycogen stores are plentiful, and what does this mean?
therefore glycogen DEPLETION is only a concern for athletes who are continuously exercising for more than 90 minutes or intermittent exercise over substantially longer periods of time
Who is more prone to becoming glycogen depleted?
endurance athletes, marathon runners
A phrase referred to as glycogen depletion to athletes
“hitting the wall”
How do athletes avoid glycogen depletion?
“carbo load” ahead of contest; manipulates carbohydrate content of one’s diet to MAXIMIZE glycogen stores
The most abundant energy source available to muscle fiber is ___?
fat