Module 2 Flashcards
What actually releases energy from ATP
Breaking the bond between ATP and ADP
what substance provides the major source of energy?
macronutrients! They have to be catabolized though
What is the equation for ATP hydrolysis
ATP + H2O -> ADP + P
what powers all forms of biological work
hydrolysis (ATP)
If you dont know the answer to a KIN course, the answer is
calcium
Under what conditions do we see a decrease in ATP levels
extreme exercise
how much ATP is stored in the body at any time
80-100 g, enough for 2-3 seconds of max exercise
where are the two sites of ATP production
mitochondria or cytosol
What ATP production process occurs in the cytosol
glycolysis
What substrates are involved in glycolysis
glucose, glycogen and NAD
What ATP production process occurs in the mitochondra
oxidative phosphorylation (ETC), beta oxidation
what cells are multinucleated
muscle cells
What kind of athletes have more intramuscular fat
endurance runners. They have high levels of fat but burn off so much of it that they’re not unhealthy
Are lipids around mitochondria good
no
How much PCr is stored in cells
4-6 times as much ATP
At what time does PCr reach its max yield
10 seconds
Summarize the chemical process behind PCr
ATP -> ADP + P + energy,
PCr+ADP->Cr+ATP+energy
what are the main substances used in metabolism
carbs, triglycerides and proteins
what are the main differences between anaerobic and aerobic glycolysis
both in oxygen supply and fate of pyruvate
describe the process of rapid glycolysis
- (Glucose + ATP) x 2
- 2 x (NAD takes two H to form NADH H to go ETC)
- 2 x (ADP forms ATP)
- 2x (H2O produced)
- 2 x (ATP produced)
- end result pyruvate
What enzyme transfers lactate and pyruvate
lactate dehydrogenase
what enzymes are important in rapid glycolysis
hexokinase, pyruvate kinase, phosphofructokinase, fructose 1 6-diphosphate
How much energy is released in rapid glycolysis
5%. 95% of the potential energy is held in the pyruvate molecule
Describe the process behind slow glycolysis
- rapid glycolysis
- pyruvate changed to acetyl coa
- Acetyl coa goes through citric acid cycle and ETC
When is the other 95% of energy released?
when pyruvate converts to acetylcoa
How many carbon do we lose per glucose
6
what are some important enzymes in the citric acid cycle
succinate dehydrogenase and citrate synthase
at what point is slow glycolysis irreversible
when we convert pyruvate to acetyl coa
citric acid cycle
- pyruvate goes through dehydrogenase with NADh and coenzyme A
- produce acetyl-CoA
- THEN citric acid cycle
- produces a bunch of H
- produce 3 NADH + H, 1 FADH, 2 CO2 and ATP
what are the key enzymes in citric acid cycle
citrate synthase and isocitrate dehydrogenase
What are oxygen’s roles in energy metabolism
- it is the major oxidizing agent
- acts as rate limiting step
- acts as final electron acceptor
what does the ETC act as
represents the final common pathway where electrons are extracted and H combines with O
What is oxidative phosphorylation
it is a process that synthesizes ATP by transferring electrons between NADH, FADH2 to oxygen
what is the “phosporylation” in oxidative phosphorylation
ADP becoming ATP
what is the equation for oxidative phosphorylation
NADH + H + 3ATP + 3P + 1/2O2 -> NAD + H2O +3ATP
define glycogenesis, glycogenloysis
glycogenesis: glycogen synthesis
glycogenolysis: glycogen breakdown
Compare fat vs CHO oxidation byproducts
CHO = 6CO2, 32ATP, 1 O2 per C
FAT = 16CO2, 129ATP, 1.5O2 per C
Define respiratory quotient
RQ = CO2 produced / O2 consumed
what does the RQ approximate
the nutrient mixture used for energy. Since carb RQ = 1, and fat RQ = 0.7, we can calculate RQ to measure which macronutrients were likely used!
What is the RQ for macronutrients
carb = 1 (6/6)
fat = 0.7 (16/23)
what is the respiratory exchange ratio
it is the ….
diff from RQ because it looks at non steady conditions, and measures via gas exchange (indirect calorimetry)
Describe anabolism
uses ATP, synthesizes end products
describe catabolism
takes carbs, turns it into ATP
How can energy transfer result in little heat loss
energy lost by one molecule can transfer to the chemical structure of another without appearing as heat
When exercise begins, what happens to a bunch of systems?
they are all activated really quickly to increase energy transfer
for each hydrogen aotm pair, what happens in the ETC
2 electrons flow down and reduce O to H2O.
the passage of e allows enough energy to take ADP -> ATP
what happens at the last protein cytochrome in the eTC
the last protein complex has strong oxygen affinity? and it discharges its electron directly onto the oxygen
what are the prereqs for constant ATP synthesis in oxidative phosphorylation
tissue availability for NADH and FADH
oxidizing agent present in tissues
sufficient enzyme and mitochondria concentrations
what imbalance is caused by inadequate oxygen
hydrogen release and terminal oxidative. it ends up with electron flow getting backed up and hydrogen accumulating to NAD and FAD
oxygen at the end of the ETC determines what
aerobic ATP capacity: max amount of ATP to be aerobically produced. low oxygen means less ATP
what activities correspond with which energy systems
ATP = sprint, golf swing, 1RM
fast glucose = sprints, hockey
aerobic CHO = 100m, 5km
fat = marathon
define lactate threshold
the point at which our body can no longer clear the lactate in our blood stream. represents the highest intensity for a period of time that we can exercise
For each kg of muscle, how much ATP does it have
3-8mmol of ATP, 4-5 times that in PCr
do movements rely exclusively on certain energy systems
Yes! Some are completely reliant on PCr
define steady state exercise
Occurs when ATP demands are equal to aerobic ATP production
define VO2 max
the max amount of oxygen someone can consume in 1 minute
When do we hit VO2 max
- when increase in ATP demands do not meet increase in ATP production
- max oxygen consumption AKA when it plateaus
define lactate threshold
the exercise intensity when lactate begins to accumulate in the blood
define oxygen deficit
how much less oxygen was actually consumed than if ATP demands were met with oxygen needs (occurs at beginning of exercise)
define excusive post exercise oxygen consumption
how much more oxygen was consumed during recovery than theoretically required at rest
When does blood lactate accumulate? What VO2 does it occur at?
most of the time at 50-55% aerobic capacity. any less, lactate production = lactate disappearance
define blood lactate threshold
exercise intensity during which lactate production exceeds lactate consumption
how does blood lactate threshold change with trained people
blood lactate threshold is higher with untrained than trained. trained perform at 80-90% max aerobic capacity
what are some of the (specific) reasons why trained people can perform at higher percentages of their VO2 max
- genetics
- local training adaptations
- rapid lactate removal
- main thing is mitochondira
What is represented by a plateau in oxygen uptake
VO2 max
what is VO2 max indicative of, ability wise
indicates ability to maintain intense exercise for longer than 4-5 minutes
what does the oxygen deficit represent
immediate anaerobic energy transfer until steady rate meets demands
what is a smaller O2 deficit in athletes explainable by?
rapid increase in bioenergetics
increase in blood flow
large blood flow to active muscle (due to cellular adaptations)
Why do marathon athletes have a higher EPOC
because they push themselves so much harder, and end up with a much heavier energy expenditure
What is the shape of the recovery VO2 curve
logarithmic. decreases by about 50% for each 30 seconds
What is the formula for EPOC
recovery VO2 - total VO2 at rest
What does the EPOC do in both short and long term
restores the body to its initial conditions!
short term = replenishes phosphates
long term = lactate resynthesized to glycogen
lactate shuttle?
with inadequate oxygen, what happens to the hydrogen ions
they fail to oxidize, causing pyruvate to convert to lactate
if lactate threshold is not hit yet, but there are increases in intensity/oxygen uptake, what happens to blood lacate
the levels remain stable
Need to understand NADH and FADH H relationships
what occurs to hydrogen when glycolytic processes predominate?
the body undergoes a shortage of oxygen, and is unable to shuttle hydrogen out. it then attaches to pyruvate to create lactate
what organ converts lactate to glucose
liver
What term describes the flattenning of oxygen uptake
steady state
What are the units of heat production
work, or joules (J)
what is a calorie?
- food calorie = Kcal
- 1kcal = 4.184 kJ
- defined as the energy required to raise 1g of water 1 degree
what is the difference between direct and indirect calorimetry
direct: measures heat controlled environment, very complicated
indirect: measures oxygen consumption, either closed or open
what is the difference between closed circuit and open circuit spirometry
closed = breathing and exhaling through tube
open = exhaling through tube
what is the division of TDEE
10% = food
15-30% = thermic effect of PA
60-75% = resting metabolic rate
how can we estimate resting daily energy expenditure
RDEE (kcal/day)= 370 + FFM (kg)
What happens to TDEE overtime, with age?
it decreases with age, peaks at 5 years old
what factors affect TDEE
- physical activity
- diet and thermogenesis
- calorigenic effect of food on metabolism
- climate
- pregnancy
how does climate affect TDEE
tropical climates result in 5-20% higher TDEE, causes about 5% higher O2 consumtpion
For each 1lb gain in fat free mass, what happens to resting metabolic rate
it increases by 7-10kcal/day
Absolute vs relative
absolute: situation is the same for all, advantage to bigger people
relative: scaled to body size, peak performance. advantage to smaller people
In what scenarios is a high body mass not as important?
in weight supported exercise. the influence of body mass on energy cost decreases considerably
how can we reduce the energy cost differences between individuals regardless of race, sex, age, size
by expressing energy cost per kg
What is 1 MET
MET: metabolic equivalent
- it is a multiple of RMR
- 1 MET = 250ml/min for men, 200mL/min for women = 3.5ml/kg/min
- exercise at 2 METS requires twice the resting metabolism
