Week 5 - Energy Systems in Exercise Flashcards
how much energy do humans produce at rest?
enough to power 100 watt lightbulb
how much O2 is burned a day?
380L
how many times can a muscle fibre contract in a second?
25 times
how many times can a muscle fibre contract in a second?
25 times
what happens our usual energy production (burning of 2,000kcal a day) when we work and exercise hard?
it increases, we produce even more energy simultaneously example Chris Hoy can generate over 2500W
what are macronutrients?
substances consumed in large quantities
what are the 3 macronutrients?
fat, carbohydrates, protein
which macronutrients contributes least to energy production?
protein
which macronutrient contributes most to energy production?
fat
can glucose be converted into fat?
yes by lipogenesis
can amino acids form glucose?
yes
what are the 3 energy systems?
phosphogen, glycolytic and oxidative
what energy system is aneraboic ?
phosphogen and glycolytic (occurs in cytosol)
what energy system is aerobic?
oxidative (occurs in mitochondria)
what occurs in the phosphogen system?
ATP Phosphorylation
what is the equation that represents the phosphogen system?
PCR + ADP +H+ <-> ATP + Creatine
what does high PCR concentration and enzymatic rate do to the system?
a decrease in ATP during high intensity exercise
what happens when PCR is producing ATP in the phosphogen system?
it can only support high ATP demands for short periods of time
what sport relies on phosphogen system?
sports with explosive movements - weightlifting and sprints and american football
what does the glycolytic system do?
converts glycogen or glucose into pyruvate and ATP
what is the rate determining enzyme in glycolytic system?
phosphofructokinase
what sport relies on glycolysis?
bursts that last 30-180 seconds like basketball
what is problematic about glycolysis?
negative feedback loop- pyruvate inhibits phosphofructokinase
what allows glyolysis to continue and much more ATP?
Pyruvate is converted into Acetyl CoA via Krebs
conversion to lactic acid
how much ATP/lactic acid do we get from 1 molecule of glucose?
2
what increases yield of ATP in glycolysis?
aerobic glycolysis in mitochondria
which is more sustainable, aerobic or anaerobic glycolysis?
aerobic
where does oxidative system take place?
mitochondria
desrcibe oxidative process
pyruvate fat and protein is converted into ATP
What processes are involved in oxidative process?
1)substrates are converted into Acetyl CoA
decarboxylation - pyruvate
beta-oxidation - fat
deamination - amino acids
2) Krebs Cycle - 2 ATP
3) oxidative phosphorylation
what system has highest rate of ATP?
Phosphogen
what system has highest yield of ATP?
Oxidative
what is the anaerobic/ lactate threshold?
maximal exercise intensity sustained by aerobic metabolism
how is anaerobic/lactate threshold measured?
maximal graded incremental test
how is anaerobic/lactate threshold measured?
maximal graded incremental test
what do we burn during exercise?
fat and carbohydrate
