Energy Flashcards
what comes out of beta oxidation
NADH, FADH2
for each 18 carbon fatty acid molecule you make what
147 molecules of ADP phospholated to ATP during beta oxidation
longer fatty acid chains go through beta oxidation more times and cut off ___ carbons each time
2 carbon chain
to run the citric acid cycle do you need glucose if you have fats and proteins
yes you need a little bit of glucose to run the citric acid cycle
takes about 30seconds for oxidative phosphorylation to turn on ___%
50%
the grade of a vo2 max test (when the incline increases or when you increase speed)
this increases the work needed
every time you change the grade in a vo2 max
your oxygen kinetics turns up every time the work increases but it takes a little bit of time so there is a lag
faster increase in vo2 in trained state;
increase tight coupling
more mitochondria
increased cardiac output
how do you fuel the work if your oxygen does not keep up
anerobic
have to use other energy pathways
energy debt and has to be payed by phosphocreatine and eventually oxidative phosphorylation turns on to make way more ATP it just takes some time to turn on
mitochondria can only burn at their maximal speed of their
enzymes
fick equation
how much oxygen is delivered and how much is used
when vo2 max happens
you either cant deliver anymore oxygen or you cant (Muscles cant) use any more oxygen or both
lactate stays relatively low in a trained person (don’t have to go into anerobic glycolysis earlier) why
trained person has a bigger cardiac output maybe have some more capillaries so they are able to be delivered more oxygen and they are able to use it faster and better
delay when they start making lactate
trained people are able to make more lactate then untrained people why
trained people have more mitochondria and better vo2maxs
have more enzymes; glycolytic enzymes! (because bigger muscles)
if youre use to having a lot of lactate so you are used to the pain so you can push through it more
have more lactate dehydrogenase
is the lactate threshold is different or the same as the ventilatory threshold
different
recovery after vo2 max
it takes time to restore your oxygen debt so it takes longer to pay it back so you must do light exercise after intense exercise to repay the debt and not pass out
how long does It take to pay back an oxygen debt
at this point your oxidative phosphorylation is going super fast because it takes time to slow down so this oxygen debt can be payed back quickly
can be payed back in 2-4 MINS
unless you are doing super intense exercise for a super long time
what is a calorie or kcal
a measure of heat, expresses a foods energy value
1 kcal equals the quantity of heat required to raise the temperature of
1kg of water 1degree Celsius
what is the British thermal unit
1 BTU = quantity of heat needed to raise the temperature of 1lb of water 1 degree F
what is a direct calorimetry
burring food in a bomb calorimeter permits the direct quantification of foods energy content (measured as heat transfer)
heat combustion
heat liberated by oxidizing a specific food
what are the average gross energy values (heat combustion) of carbs, lipids, protein
carbs= 4.2 kcal/g
varies with arrangement of carbohydrate molecule atoms
lipid= 9.4 kcal/g
varies with structural composition of molecules fatty acids
protein= 5.65 kcal/g
affected by protein type and relative N2 content
what is Awater general factors
provides useful estimate of the net energy value of typical foods a person consumes
what are the average Atwater values
carbs= 4 lipid= 9 protein= 4 alcohol= 7
the energy actually available to the body; energy intake is influenced by the __
proportion of food consumed that are actually digested and absorbed (coefficient of digestibility)
what is the average coefficient of digestibility is for carbs, lipids. and proteins
97% for carbs
95% for lipids
92% for proteins
___ can influence the coefficient of digestibility by altering the speed at which foods pass through the digestive track
dietary fiber
____ are not fully digested in the gut , which is seen as coefficient of digestibility of ____% for legume-based protein and ___% for animal based protein
proteins
78% for legume based
97% for animal based
calories represent heat energy regardless of food source which means
caloric equality
300kcal of ice cream is equal to 300kcal of French fries ect.
what does caloric equality assume but what is the actual case
it assumes that these calories are already absorbed and digested
however dietary energy intake is influenced by the proportion of food consumed that are actually digested and absorbed (coefficient of digestibility)
define the first law of thermodynamics
energy cannot be created or destroyed but only transforms form one form to another without being depleted
the boy foes not produce consume or use up energy; instead it transforms energy from one state into another as physiologic systems undergo continual change
what is the second law of thermodynamics
tendency of potential energy to degrade to kinetic energy of motion with a lower capacity for change
all of the potential energy in a system tends to degrade to kinetic or heat energy which has a lower potential to do work
system total energy =
potential energy + kinetic energy
what is potential energy
related to structure or position for example water at the top of the dam = trapped potential energy (energy of position)
what is kinetic energy
relates to energy of motion with release of heat
water at the bottom of the dam represents ____ ; and the water that cascades over the dam ___
lower potential energy
water dissipates to kinetic energy as it moves
define biosynthesis
bound in one substance directly transfers to other substances to increase their potential energy
specific building-block atoms of carbon, hydrogen, oxygen, and nitrogen become activated and join other atoms and molecules to synthesize important biologic compounds and tissues
what are energy-releasing and energy conserving processes
exergonic
endergonic
coupled recreations
what is exergonic
any physical or chemical process that releases energy to surroundings (downhill process) with free energy decline
what is endergonic
chemical reactions that store or absorb energy (uphill process) increase for biologic work
what is coupled reactions
exergonic drive endergonic
what are forms of energy; can each energy form convert or transform to another
chemical mechanical heat light electrical nuclear yes
what are two examples of energy conversion
photosynthesis
respiration
what type of energy process in photosynthesis; what happens
endergonic process
plants transfer solar energy to potential energy in carbohydrates lipids and proteins
what type of energy process in respiration; what happens
exergonic process
stored energy in plants couples to chemical compounds for biologic work
what are three forms of biologic work in humans
chemical biosynthesis of cellular molecules
mechanical - muscle contraction
transport - transfer of substances among cells
what does bioenergetics refer to
the flow and exchange of energy within a living system
what is an example of potential energy
macronutrients before releasing stored energy in metabolism
what are two factors that affect the rate of bioenergetics
enzymes- protein catalysts that accelerate chemical reaction rates without being consumed or changed in the reaction
coenzymes - nonprotein organic substances that facilitate enzyme action by binding a substrate to its specific enzyme
___speeds up (catalyze) chemical reactions; in some cases can make a chemical reaction millions of times faster
enzymes
a substrate binds to ___ site of an enzyme and is converted into ___.
active site
products
once the products leave the active site the enzyme is ready to
attach to a new substrate and repeat the process
what are some classification of enzymes
oxidoreductases transferases hydrolases lyases isomerases ligases
what are some examples of specific enzymes (note there are thousands of enzymes in the human body)
lipases amylase maltase trypsin lactase acetylcholinesterase helicase DNA polymerase
lipases
digest fat
amylase
change starch into sugars (saliva)
maltase
breaks maltose into glucose (saliva) (potatoes, pasta, beer)
trypsin
small intestine breaks proteins down
lactase
small intestine breaks lactose into glucose and galactose
acetylcholinesterase
breaks down Ach in nerves and muscles
helicase
unravels DNA
DNA polymerase
synthesize DNA from deoxyribonucleotides
what are the steps in the lock and key mechanism of an enzyme and substrate
substrate matches active site of enzyme
enzyme-substrate complex splits to yield product
enzyme now available for interaction with other substrate
according to the lock and key mechanism; enzyme turns on when its active site joins in a perfect fit with the
substrates active site
enzyme substrate lock and key interaction ensures that the
correct enzyme matches with its specific substrate to perform a particular function
do enzymes all operate at the same rate; what is this called
no
turnover number
what is the turnover number
number of moles of substrate that react to form product per mole of enzyme per unit time
what alters enzyme activity
pH and temperature
enzyme inhibition
substances inhibit enzyme activity to slow the reaction rate
what are two types of enzyme inhibition
competitive inhibition
non-competitive inhibition
what is competitive inhibition
substrates that closely resemble the target substrate but cannot be changed by the enzyme
bind to the enzymes active site - blunts enzymes ability to interact with substrate
what is non competitive inhibition
do not resemble target substrate
bind to a non-active site, altering the enzyme structure
what is michaelis-menten kinetics
in biochemistry this type of kinetics is one of the best known models of enzyme kinetics
rate of a reaction is the ____ which is referred to as V
speed of a reaction
the maximum rate of a reaction is referred to
Vmax
Km is the ____ at which the enzyme will be running at “half speed”. it is defined as ___
concentration of substrate
as the concentration of substrate that stimulates 50% Vmax
according to michaelis menten kinetics; if you increase the protein content available to catalyze the reaction ____ will increase proportionally to the increase in protein content
Vmax
Vmax is influenced by
the rate of the enzyme
competitive inhibition of an enzyme alters its ability to catalyze a reaction at ___ to ___ levels of substrate as shown by a change in the ___ of this enzyme
low to moderate
Km
Changes in Km influence enzyme activity as low to moderate substrate levels but do not influence
Vmax
some enzymes have multiple binding sites for a substrate which may be beneficial because of
cooperativity
what are examples of cooperativity
hemoglobin
SERCA (which is sarcoendoplasmic reticulum Ca2+-ATPase)
do enzymes that display cooperativity display michaelis-menten kinetics
No
in cooperativity is Vmax still the maximal turnover rate of the enzyme
yes
instead of using the term Km the term ___ is used to describe the concentration of substrate at which the enzyme will be running at “half speed”
K0.5
does the change in K0.5 during cooperativity influence enzyme activity at low to moderate substrate levels but not influence the Vmax?
yes
in biochemistry ______ is the regulation of an enzyme by binding an effector molecule at a site other then the enzymes active site
allosteric regulation (allosteric control)
post translational modification (PTM) refers to
the covalent and generally enzymatic modification of proteins following protein biosynthesis
____ is an example of a covalent modification to an enzyme; may also result in inactive depending on the enzyme
phosphorylation
what are coenzymes
complex nonprotein organic substances that assist enzyme action
how do coenzymes assist enzyme action
binding the substrate to the enzyme
transports biologic compounds from one enzyme to another
for example- nicotinamide adenine dinucleotide (NAD) is a coenzyme vital to ATP production
hydrolysis is
digest or degrade complex carbohydrate lipid and protein molecules into simpler forms the body absorbs and assimilates
splits chemical bonds by adding H+ and OH- to the reaction byproducts
condensation is
structural components of nutrients bind together to form more complex molecules and compounds
oxidation is
reactions that transfer oxygen hydrogen atoms or electrons
oxidation always involves electron gain/loss
loss
loss of electrons in oxidation always occurs with a
net gain in valence
reduction is
any process in which atoms in an element gain electrons with a corresponding net decrease
reduction always involves electron gain/loss
gain
reducing agent is
substance that donates or loses electrons as it oxidizes
oxidizing agent is
substance being reduced or gaining electrons
as intensity of exercise increases and oxygen supply (for use) becomes reduced some pyruvate
gains 2 hydrogen electrons and becomes reduced to form lactate
during recovery when oxygen supply is adequate lactate
loses 2 electrons and oxidizes back to pyruvate
____ is a key molecule in redox reactions
NAD+
what are the 4 redox reactions
glycolysis
citric acid cycle
electron transport chain
beta oxidation
oxidation and reduction reactions constitute the biochemical mechanism that
underlies energy metabolism
mitochondria remove electrons from hydrogen and eventually
pass them to oxygen atoms
which is ATP synthesis occurs during redox reactions
where does oxidative phosphorylation occur
in the mitochondria
what is the cristae
the inner membrane is folded to maximize surface area
what happens in the matrix
krebs or citric acid cycle enzymes which make some ATP and a lot of NADH and FADH2 to power the electron transport chain
what does the electron transport chain do
proteins that harness the energy released by reducing the energy level of one electron to create a H ion gradient to power the generation of ATP
what is the respiratory chain
transport of electrons by specific carrier molecules
the electron transport chain is the final common pathway in what metabolism
aerobic metabolism
during the electron transport chain for each pair of hydrogen atoms ____electrons flow down the chain and reduce ____ oxygen atom
2 electrons
1 oxygen
how does the electron transport chain process end
when oxygen accepts two hydrogen electrons and forms water
what are two electron carriers
NAD and FAD
NAD is reduced to ____ during ___ and during ____
NADH in glycolisis and citric acid cycle
FAD is reduced to FADH2 in the
citric acid cycle
for every NADH how many ATP are produced
3
for every FADH2 how many ATP are produced
2
where does NADH go in the electron transport chain
complex 1
where does FADH2 go in the electron transport chain
complex 2
the six forms of energy include
chemical mechanical heat light electrical and nuclear
energy transfer in humans appear in three forms of biological work
chemical mechanical or transport
enzyme kinetic properties can be altered by
regulatory pathways
hydrolysis and condensation reactions form the basis of
digestion and synthesis
redox reactions provide the basis for the
body’s energy transfer processes
macronutrient fuel sources
triacylglycerol and glycogen molecules stored within muscle cells
blood glucose
free fatty acids
intramuscular- and liver derived carbon skeletons of amino acids
anaerobic reactions in the initial phase of glucose break down
phosphorylation of ADP by PCr under enzymatic control by creatine kinase and adenylate kinase
the cells two major energy-transforming activities are
extract potential energy from food and conserve it within the ATP bonds
extract and transfer the chemical energy in ATP to power biologic work
cells contain only a small quantity of ATP so it must
continually be resynthesized
ATP levels decrease in skeletal muscle only
under extreme exercise conditions
the body stores 80-100g of ATP at any time under normal resting conditions this is enough stored energy to power
2-3 seconds of maximal exercise
how is ATP produced
by the citric acid cycle respiratory chain and glycolysis
the citric acid cycle and respiratory chain are anaerobic or aerobic
aerobic
what is used in the citric acid cycle and respiratory chain to produce ATP
fatty acids
pyruvate from glucose
some deaminated amino acids
glycolysis is anaerobic or aerobic
anaerobic
what is used in glycolysis to produce ATP
phosphocreatine
glucose/glycogen
glycerol
some deaminated amino acids
at the beginning of exercise in the untrained state the accumulation of ADP is countered by HEPT +
glycolysis
during the beginning of exercise in the untrained state the body uses HEPT and glycolysis which ends up over producing ____ this then triggers _____ to begin
ADP
oxidative phosphorylation
what remains elevated after exercise stops, why?
oxidative phosphorylation
in order to remove ADP by regenerating PCr
6 minutes of high intensity cycling at 90% VO2max leads to
big changes in ATP and proportional increases in ADP
what are the High energy phosphate transfer
ATPase (breaks down stored ATP with water)
Creatine Kinase(ATP + Cr or ADP +PCr +H)
Adenylate Kinase(ADP+ADP or ATP+AMP)
AMP Deaminase (AMP to IMP + NH3)
phosphocreatine is the
energy reservoir
some energy for ATP resynthesize comes from anaerobic splitting of a
phosphate from phosphocreatine
cells store approaximalty ___to____X more PCr than ATP
4-6times
PCr reaches its maximum energy yield in about
10seconds
____ is impacted following 6 minutes of high intensity cycling at 90% VO2max as a way to buffer changes in ATP
phosphocreatine
oxygen utilization (VO2) takes time to turn on while cycling at 90% VO2max until VO2 is able to create sufficient ATP through oxidative metabolism there will be a
challenge to ATP homeostasis
as intensity of exercise increases and oxygen supply becomes reduced some pyruvate gains 2 hydrogen electrons and becomes ______ to form ___
reduced to form lactate
during recovery when oxygen supply is adequate lactate loses 2 electrons and ____ back to ___
oxidizes back to pyruvate
does metabolism and metabolic pathways work one at a time in order
no they all happen simultaneously if the substrates are available the enzymes are ready to do their job even if some of the enzymes require time to turn on
ATP homeostasis is balance of
energy utilized by cellular ATPases and energy produced by metabolic pathways
at rest ATP utilization = ____ umol ATP/gmuscule/second
0.01
during exercise ATP utilization = ____ umolATP/ gmuscle/second
10
the net depletion of ATP in muscle rarely goes below __% because
30% because ATP utilization pathways are tightly coupled to ATP metabolic pathways
it could be said that ATP utilization or ADP production controls the
rate of metabolic ATP production in order to regulate ATP homeostasis
ATP homeostasis is regulated by what ratio
ATP:ADP
what does the term tight coupling mean
the term used to describe the regulation of ATP homeostasis and is generally used to describe how well the system matches ATP production with ATP utilization
a tightly coupled system will have
small changes in ATP:ADP ratio because ATP production is tightly coupled with ATP utilization
what impact does exercise training have on how quickly metabolic pathways turn on
big changes in ATP after each bout of exercise which was not altered by training
big changes in ADP in the first bout which did not occur during the last bout
what changes in ____ , ____ , ____ and ____ after exercise follow the first and second bouts of exercise where these changes the same after exercise following the 9th and 16th bout
PCr ADP AMP and IMP
no much smaller changes
why did ADP homeostasis become more tightly regulated following high intensity interval training
VO2 during the 1st minute of exercise in the first and second bouts of exercise were similar
VO2 during the 1st minute of exercise were significantly higher during the 7th and 15th bouts of exercise, which shows that VO2 kinetics turned on much faster
glycolysis can power about ___ seconds of contraction
30 seconds
what are the two phases of glycolysis
energy investment phase and energy generation phase
if we start with glycogen in glycolysis how many ATP is used in the energy investment stage
only 1
what are the two forms of carbohydrate breakdown
anaerobic (rapid glycolysis)
aerobic (slow glycolysis)
what does anaerobic rapid glycolysis result in during carb breakdown
results in pyruvate to lactate formation with the release of about 5% of energy within the original glucose molecule
what does aerobic slow glycolysis result in during carb breakdown
results in pyruvate to acetyl-coA-to-citric acid cycle and electron transport chain of the remaining energy within the original glucose molecule
what is glycolysis regulated by
concentration of glycolytic enzymes hexokinase, phosphofructokinase and pyruvate kinase
levels of the substrate fructose 1,6-disphosphate
oxygen
glycolysis makes
pyruvate
if pyruvate enters the krebs cycle and there is no pyruvate left to convert in to lactate then
lactate will not be produced because lactate will only form when pyruvate concentrations are so high that all of it cannot enter the mitochondria
lactate is generated when
pyruvate production from glycolysis exceeds the rate of pyruvate entry into the mitochondria
when lactate is produced it can alter the cellular pH and the acidity does what
impairs excitation contraction coupling processes which leads to muscle fatigue
pyruvate concentrations were increased by exercise in all bouts but the amount of it what became lactate was significant less in the last bout why
due to tighter coupling of oxidative phosphorylation with ADP regeneration since more ATP is being produced by the mitochondria which is shown on the VO2 data table and also indicated here by less lactate being produced and less pyruvate accumulating in the muscle after training
in the trained state what is different about the HEPT and glycolysis then in the untrained state during exercise
in the trained state HEPT and glycolysis are not relied upon quite as heavily after training because oxidative phosphorylation is able to contribute to the removal of ADP sooner during exercise
oxidative phosphorylation is activiated much earlier in the trained state due to
an increase in mitochondria a
an increased sensitivity of metabolic enzymes for ADP
an increase in oxygen delivery to working muscle
collectively they all contribute to tighter coupling of ADP production with ATP regeneration
like in the untrained state the trained state oxidative phosphorylation remains elevated after exercise to remove ADP by regenerating PCr but what is different
the total ADP content is less in a tightly coupled system so the oxygen debt is paid back faster
what are the 5 sources of carbohydrate metabolism
muscle glycogen glucose liver glycogen lactate CHO ingestion
what is glycogenesis
glycogen synthesis
surplus glucose forms glycogen in low cellular activity and or with depleted glycogen reserves
what is glycogenolysis
glycogen breakdown
glycogen reserves break down to produce glucose in high cellular activity with glucose depletion
what are key enzymes (where do they occur)
hexokinase (step 1)
phosphofuctokinase (step 3)
occurs in the cytoplasm
what are reactions that occur in the cytoplasm
NAD reduced to NADH + H ( step 6)
substrate phosphorylation (step 7&10)
pyruvate or lactate production
what is the net production of ATP in glycolysis when using glucose
2 ATP
what is the net production of ATP in glycolysis when using glycogen
3 ATP
for each glucose molecule that is derived from blood glucose that enters glycolysis there is a net total of ____ATP generated
2
for each glucose molecule that is derived from glycogen molecule that enters glycolysis there is a net total of ___ ATP generated
3
pyruvate is brought into the mitochondria through the
pyruvate dehydrogenase (PDH) enzyme
pyruvate dehydrogenase
pyruvate + NAD + Coenzyme A —-> acetyl-CoA + CO2 + NADH + H
activation of PDH? is promoted by any sudden demands upon the cell signalled by
Ca
should lactate be viewed as a waste product hy
no
it contributes to increased acidic environment and there is always some lactate production from red blood cells or enzymatic limitations and this lactate can be used to
provide energy for other cells
manufacture glucose
____ speeds up glycolysis
exercise
the electron transport chain pumps what
protons across inner mitochondrial membrane
explain the coupling of electron transport and oxidative phosphorylation
1) energy-releasing reactions of oxidation-reduction (electron transport) create a proton (H) gradient across the inner mitochondrial membrane
2) stored energy of the proton gradient plus the inner mitochondrial membrane potential provide the electrochemical basis for coupling electron transport to oxidative phosphorylation to form ATP
aerobic glycolysis results in __ entering the mitochondria
pyruvate
what are the key enzymes in the citric acid cycle
citrate synthase
succinate dehydrogenase
enzymes in the krebs cycle are constant proportion to each other and exercise training can
increase mitochondria number which leads to similar increases in all krebs cycle enzymes
the electron transport chain represents the final common pathway where electrons extracted from
hydrogen pass to oxygen
mitochondrial oxygen levels drive the respiratory chain by serving
as the final electron acceptor to combine with hydrogen to form water
what is oxygens role in energy metabolism
serves as the major oxidizing agent in tissues
ensures that energy transfer reactions proceed at appropriate rate
aerobic metabolism refers to
energy-generating catabolic reactions where oxygen serves as the final electron acceptor in the respiratory chain to combine with hydrogen to form water
oxidative phosphorylation synthesizes ATP by
transferring electrons from NADH and FADH2 to oxygen
more the __% of ATP synthesis takes place in the respiratory chain by oxidative reactions coupled with phosphorylation
90%
mitochondria remove electrons from hydrogen and eventually pass them to
oxygen atoms
ATP synthesis occurs during ___ reactions
redox
oxidative phosphorylation process in which NADH + H and FADH2 are oxidized in the Electron transport chain (H passes to o2) and the energy released is
used to synthesise ATP from ADP and Pi
what are the two stages of the oxidative phosphorylation
electron transfers release energy that is used to pump H across the membrane and thus generate an electrochemical gradient (stored potential energy)
H flow back down the gradient through ATP synthase which catalyzes the production of ATP
how energy is transferred is known as
chemiosmotic hypothesis
how does the body harness potential gradients
gradients (both energy and concentration)
its the coupling mechanism that binds ADP and a phosphate ion to synthesize ATP
what is the net energy transfer from glucose catabolism
32 ATP
substrate phosphorylation reacting in glycolysis produces how many ATP, the remaining 4 H produced in glycolysis makes how many ATP
2
5
the 3 H that is used in the pyruvate to acetyl coA reaction makes how many ATP
5
how many ATP is made in the citric acid cycle (by substrate phosphorylation and by the H)
2 (substrate phosphorylation)
15(12 H)
3 (4H)
the rate of oxidative phosphorylation is mostly determined by the availability of ___
exercise requires work to be done which burns ATP into ADP that increase in ADP speeds up ___
ADP
o2 consumption in the ETC
a reduction in NADH concentration lifts the break on pyruvate oxidation so the mitochondria turns on the krebs cycle to
generate a lot more NADH and FADH2
speeds up NAD and FAD regeneration
compounds that either inhibit or activate enzymes in the oxidative pathways modulate regulatory control of
glycolysis and the citroc acid cycle
what serves as enzyme inhibitors
ATP and NADH
what functions as enzyme activators
ADP and NAD
cellular ADP concentration exerts the greatest effect on __ what do other modulators include
the rate limiting enzymes that control macronutrient energy metabolism
cellular levels of phosphate, cyclic AMP, AMPK, Ca, NAD, citrate and pH
what are three specific energy sources for fat catabolism
triacylglycerols (stored directly in muscle mitochondria)
circulating triacylglycerol’s
(in lipoprotein complexes)
circulating free fatty acids (from triacylglycerol’s in adipose tissue)
complete oxidation of triacylglycerol molecule yields about ___ATP molecules
460
how does triacylglycerol yield 460 ATP
1 molecule glycerol through the glycolysis and citric acid cycle makes 19ATP
3 moleucles of 18 carbon fatty acid through Beta-oxidation and the citric acid cycle makes about 441 ATP
fat catabolism in adipocytes releases fatty acids into the blood (7 steps)
breakdown of triacylglycerol to free fatty acids
transport of free fatty acids in the blood
uptake of free fatty acids from blood to muscle
preparation of fatty acids for catabolism
entry of activated fatty acid into muscle mitochondria
breakdown of fatty acid to acetyl coA via beta oxidation and the production of NADH and FADH
coupled oxidation in krebs cycle and ETC
increase hormone sensate lipase leads to
free fatty acid delivery
epinephrine and norepinephrine (catecholamine)
glucagon
growth hormone
hormonal release triggered by exercise stimulates
adipose tissue lipolysis to further augment FFA delivery to active tissue
glycerol catabolism
substrate phosphorylation degrades pyruvate to form ATP
hydrogen atoms pass to NAD and the citric acid cycle oxidizes pyruvate
complete breakdown of a single glycerol molecule synthesises 19 ATP molecule
fatty acid catabolism
fatty acids are transformed into acetyl CoA in mitochondria via beta oxidation for entry into the citric acid cycle
explain beta oxidation:
once the fatty acyl CoA is transported into the mitochondrial matrix it passes through
beta oxidation
beta oxidation reactions remove __ carbons to form one acetyl coa to enter the citric acid cycle and one NASH+H and on FADH2 along the way
2
the fatty acyl CoA carbons are removed two at a time to continue forming
acetyl CoA and reducing equivalents until totally degraded
is it unclear if the same signals (Ca ADP AMP redox state) regulate beta oxidation like they do the other metabolic pathways
yes
is it likely that substrate availability fatty acyle-CoA NAD and FAD are the dominant activators beta oxidation
yes
the most effective way to enhance the beta oxidation pathway is to
increase mitochondrial content
for each carbon fatty acid molecule, 147 molecules of ADP phosphorylated to ATP during beta-oxidation and citric acid cycle metabolism;
knowing that each triacylglycerol molecule contains three fatty acid molecules how many ATP molecules come from one triacylglycerol
3 fatty acid molecules X 147 ADP=147 ATP
each triacylglycerol molecule also contains 1 glycerol so count the 19 ATP molecules that form during glycerol breakdown
citric acid cycle provides the vital link between
macronutrient energy and chemical energy in ATP
and also serves as metabolic hub to shuttle intermediates that cross the mitochondrial membrane into the cell cytosol to synthesize nutrients for maintenance and growth
fats burn in a carbohydrate flame is a phrase that captures the fact that
fats are turned into ATP through the krebs cycle and oxidative phosphorylation. the krebs cycle requires some intermediate substrates that come from pyruvate which is a carb source, the krebs cycle is unable to function without it
in order to burn fats there needs to be some level of
aerobic glycolysis
what are the major metabolic interconversions while storing potential energy to be accessed later
carbohydrates covert to fats by lipogenesis or nonessential amino acids
fats convert to nonessential amino acids
proteins convert to carbohydrates or fats
energy allocations progress on a
continuum
what is the oxygen deficit
expresses difference between o2 consumed during exercise and what would have been consume had the steady rate begun from the start
how is there a faster increase in VO2 in trained state
increase bioenergetics
increase cardiac output (Q)
increase regional blood flow coupled with cellular adaptations
when will muscle lactate form
when insufficient oxygen is available to fuel oxidative phosphorylation
high energy phosphates will buffer ATP concentrations for a period of time during _____ but will eventually not be able to fuel the
intense exercise
ATP demand of muscle contractions
pulmonary ventilation and lactate versus o2 consumption
lactic acid + sodium bicarbonate –> Na lactate + carbonic acid __> water + carbon dioxide
lactic acid + NaHCO3–> Na lactate + H2CO2–> H20 + CO2
what is the immediate energy system
ATP-PCr
what is the short term energy system
glycolysis
what is the long term energy system
aerobic
EPOC following exhaustive exercise
resynthesize ATP and PCr
resynthesize lactate to glycogen (cori cycle)
oxidize lactate in energy metabolism
restore oxygen to myoglobin and blood
thermogenic effects of elevated core temperature
thermogenic effects of hormones (catecholmines)
effects of elevated heart rate ventilation and other elevated physiologic functions
