exercise phys exam 2 Flashcards
lactate threshold
the point where there is a sudden increase in blood lactate concentration during the incremental test
Fick equation
vo2=CO x (a-v O2)
O2 drift
vo2 gradually increases despite intensity staying the same
what influences O2 drift
- hot environment
- high intensity
vo2 max
the plateau in vo2 despite intensity getting harder
RER equation
VCO2/VO2
produced/consumed
an RER of 1 is relying on what?
carbs
an RER of 0.70 is relying on what?
fats
crossover concept
rely less on fats and more on carbs as intensity increases
lactate during exercise acts as a?
signaling metabolite
lactate reduces what?
lipolysis
short term high intensity exercise relies on what system
ATP-PC system
as duration of high intensity exercise goes on, what do you rely on?
anaerobic glycolysis
prolonged low intensity exercise relies on what?
aerobic metabolism
what does aerobic metabolism use as fuel?
carbs and fats
what is the rate limiting enzyme of glycolysis?
phosphofructokinase (PFK)
what molecule must be used to start the krebs cycle?
acetyl coa
what is the prep step?
pyruvate being converted to acetyl coa
how many NADH get formed from pyruvate
2 NADH
how many ATP does NADH yield?
2.5 ATP
how many ATP does FADH yield?
1.5 ATP
what is the rate limiting enzyme of the krebs cycle?
isocitrate dehydrogenase
how many ATP is each acetyl coa worth?
10 ATP
why does the krebs cycle happen twice?
because there are 2 pyruvates that get converted into 2 acetyl coa
how many molecules are yielded after the krebs cycle?
4 NADH (one comes from prep step)
1 FADH
1 ATP
how many ATP do 4 H+ yield?
1 ATP
what is the total yielded ATP from glycolysis and the krebs cycle when starting with glucose?
32 ATP
the glycerol backbone is worth how many ATP?
19 ATP
what enzyme breaks down triglycerides?
hormone sensitive lipase
what are the fuel sources of aerobic metabolism?
- pcr
- glucose
- glycogen
what are the fuel sources for anaerobic metabolism?
- fats
- glucose
- glycogen
what is beta oxidation?
converting fatty acids to acetyl coa
each cut of carbons yields how many ATP?
4 ATP
what is the total yielded ATP from glycolysis and the krebs cycle when starting with glycogen?
33 ATP
what is the rate limiting enzyme of the atp pc system?
creatine kinase
what is the rate limiting enzme of the electron transport chain?
cytochrome oxidase
what is the first line of defense when you deplete ATP?
pcr system
what is the end product of aerobic glycolysis?
2 pyruvate
what is the end product of anaerobic glycolysis?
2 lactate
what is the function of enzymes?
lower rate of activation
what will an increase in temperature do to enzymes?
increase enzyme activity
at rest what metabolism produces ATP
aerobic metabolism
oxygen deficit
lag in oxygen uptake at beginning of exercise
phase II of oxygen uptake kinetics how long it takes to get to?
63% of steady state
phase III is what?
steady state
a smaller oxygen deficit relies on?
less anerobic metabolism
a bigger oxygen deficit relies on?
more anerobic metabolism
what does EPOC stand for?
excess post exercise oxygen consumption
what is EPOC?
when oxygen uptake remains elevated above rest into recovery
what are the three energy systems?
- ATP PC
- glycolysis
- oxidative phosphorylation
during low intensity exercise, what is the main fuel source?
plasma FFA
during high intensity exercise, what is the main fuel source?
muscle glycogen
what are the muscle fuel sources?
- muscle glycogen
- plasma glucose
- plasma FFA
- muscle triglycerides
In general, as exercise duration increases _____ are utilized less and _____ are utilized more
muscle stores, circulating sources
Which of the following are true statements about a trained subject engaging in aerobic activity vs an untrained individual?
they produce less lactate
Which of the following is true of hormone sensitive lipase?
it is inhibited by lactase
rapid portion of EPOC
- replenish muscle + blood O2 stores
- resyntheis of stored pc
slow portion of EPOC
- lactate converts to glucose
- elevated body temp
- elevated HR and breathing
- elevated epinephrine + norinephrine
Which of the following is required to trap glucose in the cell, enabling glycolysis to occur?
hexokinase
