Chapter 3 Flashcards
metabolic specificity
exercise modes that can “select” energy systems/metabolic pathways
bioenergetics
the understanding of macronutrient conversion into biologically usable energy
catabolism
the breakdown of large molecules to small molecules
associated with the release of energy
anabolism
synthesis of larger molecules from smaller ones
accomplished using energy released from catabolic reactions
exergonic reaction
energy releasing reaction
generally catabolic
endergonic reaction
definition, example
require energy input
usually anabolic process
ex: contraction of muscle
metabolism
the total of all exergonic and endergonic reactions in a biological system
adenosine triphosphate (ATP)
intermediate that allows the transfer of energy from exergonic to endergonic reactions
it is necessary for muscular activity and muscular growth
hydrolysis
water molecule breaking down another molecule to yield energy
adenosine triphosphatase (ATPase)
enzyme that catalyzes the hydrolysis of ATP
myosin ATPase
catalyzes hydrolysis of ATP for crossbridge recycling
calcium ATPase
catalyzes hydrolysis of ATP to pump calcium into the sarcoplasmic reticulum from vescicles
sodium-potassium ATPase
maintains sarcolemmal concentration gradient after depolarization
ATP hydrolysis formula with ATPase
ATP + H2O ADP + Pi + H+ + Energy
adenosine diphosphate (ADP)
product of ATP hydrolysis.
only has 2 phosphate groups
inorganic phosphate (Pi)
a byproduct of ATP hydrolysis
adenosine monophosphate (AMP)
product of ADP hydrolysis
anaerobic process
doesn’t require the presence of oxygen
aerobic process
requires oxygen
phosphagen system (characteristics)
- anaerobic system
- relies on ATP hydrolysis and creatine phosphate breakdown
glycogen system
aerobic? anaerobic? substrate?
- anaerobic system
- uses glucose as substrate
Krebs cycle
substrate? what system? how many ATP?
- aerobic mechanism
- oxidizes Acetyl-CoA (from pyruvate)
- part of the oxidative system
- produces 30 ATP
Oxidative system
when is it used, substrates
- source for ATP at rest and low intensity activities
- uses carbs (30%) and fats (70%) as substrates
mitochondria
the site where aerobic energy processes occur
ATP synthesis from CP (formula)
ADP + CP –> ATP + Creatine
creatine phosphate (CP)
aka
phosphocreatine (PCr)
molecule that replenishes ATP by supplying ADP with a phosphate group
ATP stores
storage, max reduction
- 80g - 100g in storage
- max decrease of 50% - 60%
adenylate kinase reaction
aka
myokinase reaction
(formula, definition, purpose)
single enzyme reaction in phosphagen system that helps replenish ATP
2ADP -> ATP + AMP
glycolysis
characteristics
the breakdown of carbohydrates to resynthesize ATP
- it is a multi reaction process
- not as rapid as phosphagen system
- higher ATP capacity than phosphagen system
law of mass action
aka
mass action effect
concentrations of reactants and/or products in solution determines direction of reaction
near-equilibrium reaction
examples
reaction that goes in direction dictated by reactant concentrations due to law of mass action.
(adenylate kinase reaction, creatine kinase reaction, ATPase reaction)
pyruvate
& it’s 2 paths
the end result of glycolysis
- converted to lactate in sarcoplasm (anaerobic glycolysis)
- shuttled to mitochondria (aerobic glycolysis)
anaerobic glycolysis
aka
fast glycolysis
(& ATP yield)
occurs when pyruvate is converted to lactate
produces 2ATP
aerobic glycolysis
aka
slow glycolysis
pyruvate undergoes the Krebs Cycle
metabolic acidosis
cause, results
H+ accumulation from ATP hydrolysis = lower intracellular pH which inhibits glycolytic reactions and disrupts calcium binding, crossbridge recycling, and enzymatic turnover
gluconeogenesis
the creation of glucose from non-carbohydrate sources in the body
Cori cycle
accumulated lactate is sent to liver and converted to glucose/glycogen.
Glucose is sent to and used in muscles which produces lactate
formula for glycolysis when pyruvate is converted to lactate
Glucose + 2Pi + 2ADP → 2Lactate + 2ATP + H2O
energy substrate
a substance used by the energy systems
nicotinamide adenine dinucleotide (NADH)
- 2 accompany pyruvate to the mitochondria at beginning of Krebs cycle
- produces 3 ATP in ETC
reaction formula for glycolysis when pyruvate —> mitochondria
Glucose + 2Pi + 2ADP + 2NAD+ →
2Pyruvate + 2ATP + 2NADH + 2H2O
phosphorylation
the addition of an inorganic phosphate to another molecule
oxidative phosphorylation
resynthesis of ATP in the Electron Transport Chain using NADH and FADH2
Substrate-level phosphorylation
&how many ATP
ADP –> ATP through 1 reaction
(produces 4 ATP in slow glycolysis;
2 ATP in Krebs cycle)
glycogenolysis
the breakdown of glycogen
3 important glycolytic enzymes
hexokinase, phosphofructokinase (PFK), pyruvate kinase
allosteric inhibition
end product of enzyme reaction binds to allosteric site on enzyme to decrease turnover rate (product formation rate)
allosteric activation
an activator binds to enzyme allosteric binding site which increases turnover rate
hexokinase
function, characteristics
catalyzes phosphorylation of glucose to glucose-6-phosphate.
phosphofructokinase (PFK)
function, characteristics, inhibitors?, activator?
catalyzes transition of fructose-6-phosphate to fructose 1, 6-bisphosphate which causes the cell to metabolize glucose instead of storing it as glycogen
most important regulator of glycolysis. it is the rate limiting step.
activated by AMP, ammonia
inhibited by ATP
pyruvate kinase
function, inhibitors?, activators?
phosphoenolpyruvate –> pyruvate
inhibited by ATP, acetyl-CoA
activated by AMP, fructose-1, 6-bisphosphate
lactate threshold
definition, what VO2 max?, what system causes this)
the exercise intensity where blood lactate begins to abruptly increase.
Untrained - 50% - 60% VO2 max
Trained - 70% - 80% VO2 max
it represents increased reliance on anaerobic mechanisms of energy production
onset of blood lactate accumulation (OBLA)
happens at 4mmol/L
a second increase in rate of lactate accumulation
flavin adenine dinucleotide (FADH2)
- produced from pyruvate in mitochondria
- produces 2 ATP in ETC
yield of oxidative system
total? from glucose? from glycogen?
40 total
Net 38 ATP from glucose
Net 39 ATP from glycogen
beta oxidation
series of reactions that break down free fatty acid
triglyceride oxidation yield
300+ ATP
creatine depletion
- 5-30 secs 50%-70%. and can be almost completely depleted
ATP depletion (max)
- 50%-60% max
- never completely depleted
ATP repletion (time)
3-5 minutes
CP repletion (time)
8 minutes
oxygen deficit
the anaerobic contribution to the total energy cost of exercise before the aerobic system kicks in
oxygen debt/Excess postexercise oxygen consumptionEPOC
the recovery O2 after exercise consumed to restore the body to preexercise conditions
interval training
a method that uses work:rest intervals to optimize energy transfer through bioenergetic adaptions
importance of work:rest ratios
allows more work to be accomplished at higher intensities with the same or less fatigue than continuous exercise
high-intensity interval training (HIIT)
brief repeated bouts of high intensity exercise with intermittent recovery periods
HIIT variables (9)
and 4 most important variables
- mode of exercise
- intensity of active segment
- duration of active segment
- intensity of recovery segment
- duration of recovery segment
- number of duty cycles in each set
- number of sets
- rest time between sets
- intensity of rest between sets
periodization
developing anaerobic + aerobic systems in preseason and transitioning to sport specific HIIT during season
combination training (cross-training)
definition, pros, cons
adding aerobic endurance training to the training of anaerobic athletes
pros: enhances recovery
cons: reduces strength, speed, and power performance
phosphagen W:R
power %, exercise time, W:R range
90% - 100% of power
5s - 30s
1:12 - 1:20
fast glycolysis W:R
power %, exercise time, W:R range
75% - 90%
15s - 30s
1:3 - 1:5
slow glycolysis W:R
power %, exercise time, W:R range
30% - 75%
1min - 3mins
1:3 - 1:4
oxidative system W:R
power %, exercise time, W:R range
20% - 30%
> 3mins
1:1 - 1:3
