Lecture 11 Flashcards
Energetics
what is metabolism
sum of all chemical reactions in the body
what is a metabolic pathway
a series of individual reactions that result in the formation of an end product
what are the two functions of metabolic pathways
catabolism = breakdown of energy yielding molecules
anabolism = building energy yielding molecules
what is the 1st law of thermodynamics
energy cannot be created or destroyed; it can only be converted from one form to another
what is the 2nd law of thermodynamics
systems tend to go from a high to a low state of potential energy
what is free energy
energy from a reaction that can be used for work
- chemical potential energy drives mechanical work of exercise
is ATP stored in the body
only a very small amount is stored in muscle and other cells
is anabolism endergonic or exergonic
anabolism is endergonic
is catabolism endergonic or exergonic
catabolism is exergonic
what is an exergonic reaction
releasing energy = “downhill” process
what is an endergonic reaction
requiring energy = “uphill process”
why are some reactions coupled
because some reactions require energy so they can be coupled with a reaction that releases energy so they both occur spontaneously
maximal sustainable exercise intensity depends on ….
factors limiting energy transfer
what are factors that affect energy transfer
- mass action
- enzymes (activity)
- co-enzymes
- temperature
- pH
what is mass action (factor affecting energy transfer)
mass action ratio = product / substrate
- the reaction will move in the direction that has less according to the mass action ratio
what are enzymes role
they act as catalysts
are enzymes reusable
yes they are
are enzymes substrate specific
yes they are
what is the role of co-enzymes
facilitate action of enzymes
- help bind substrate with enzyme
- temporary carrier of intermediary proteins
where is creatine phosphate stored
in muscle
what is creatine phosphate continually regenerated from
from free creatine
where is free glucose found and is it maintained
in the blood stream (limited), little in muscle
- maintain fairly constant - this is important
where is glycogen stored and which store is used first
stored in the muscle and the liver
- the muscle is used first
why is muscle glycogen used first
it is already in the muscle so doesn’t need to be transported
what happens when liver glycogen is used
- liver glycogen broken down to glucose
- into blood
- into muscle
- transported across muscle membrane
do you ever just use one energy system at a time
no, we use a combination of energy systems, one will most likely be more dominant depending on what we are doing
how quickly will the phosphocreatine energy system deplete
within seconds
how quickly will the anaerobic glycolysis system deplete glycogen and what does it produce
minutes
- produces lactate
how quickly will the aerobic glycolysis energy system deplete
moderate rate
- ~ hours
how quickly will the aerobic lipolysis energy system deplete
slowly
~ days
