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Flashcards in Energy Deck (247)
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1
Q

what comes out of beta oxidation

A

NADH, FADH2

2
Q

for each 18 carbon fatty acid molecule you make what

A

147 molecules of ADP phospholated to ATP during beta oxidation

3
Q

longer fatty acid chains go through beta oxidation more times and cut off ___ carbons each time

A

2 carbon chain

4
Q

to run the citric acid cycle do you need glucose if you have fats and proteins

A

yes you need a little bit of glucose to run the citric acid cycle

5
Q

takes about 30seconds for oxidative phosphorylation to turn on ___%

A

50%

6
Q

the grade of a vo2 max test (when the incline increases or when you increase speed)

A

this increases the work needed

7
Q

every time you change the grade in a vo2 max

A

your oxygen kinetics turns up every time the work increases but it takes a little bit of time so there is a lag

8
Q

faster increase in vo2 in trained state;

A

increase tight coupling
more mitochondria
increased cardiac output

9
Q

how do you fuel the work if your oxygen does not keep up

A

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

10
Q

mitochondria can only burn at their maximal speed of their

A

enzymes

11
Q

fick equation

A

how much oxygen is delivered and how much is used

12
Q

when vo2 max happens

A
you either cant deliver anymore oxygen 
or
you cant (Muscles cant) use any more oxygen 
or 
both
13
Q

lactate stays relatively low in a trained person (don’t have to go into anerobic glycolysis earlier) why

A

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

14
Q

trained people are able to make more lactate then untrained people why

A

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

15
Q

is the lactate threshold is different or the same as the ventilatory threshold

A

different

16
Q

recovery after vo2 max

A

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

17
Q

how long does It take to pay back an oxygen debt

A

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

18
Q

what is a calorie or kcal

A

a measure of heat, expresses a foods energy value

19
Q

1 kcal equals the quantity of heat required to raise the temperature of

A

1kg of water 1degree Celsius

20
Q

what is the British thermal unit

A

1 BTU = quantity of heat needed to raise the temperature of 1lb of water 1 degree F

21
Q

what is a direct calorimetry

A

burring food in a bomb calorimeter permits the direct quantification of foods energy content (measured as heat transfer)

22
Q

heat combustion

A

heat liberated by oxidizing a specific food

23
Q

what are the average gross energy values (heat combustion) of carbs, lipids, protein

A

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

24
Q

what is Awater general factors

A

provides useful estimate of the net energy value of typical foods a person consumes

25
Q

what are the average Atwater values

A
carbs= 4
lipid= 9
protein= 4
alcohol= 7
26
Q

the energy actually available to the body; energy intake is influenced by the __

A

proportion of food consumed that are actually digested and absorbed (coefficient of digestibility)

27
Q

what is the average coefficient of digestibility is for carbs, lipids. and proteins

A

97% for carbs
95% for lipids
92% for proteins

28
Q

___ can influence the coefficient of digestibility by altering the speed at which foods pass through the digestive track

A

dietary fiber

29
Q

____ are not fully digested in the gut , which is seen as coefficient of digestibility of ____% for legume-based protein and ___% for animal based protein

A

proteins

78% for legume based

97% for animal based

30
Q

calories represent heat energy regardless of food source which means

A

caloric equality

300kcal of ice cream is equal to 300kcal of French fries ect.

31
Q

what does caloric equality assume but what is the actual case

A

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)

32
Q

define the first law of thermodynamics

A

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

33
Q

what is the second law of thermodynamics

A

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

34
Q

system total energy =

A

potential energy + kinetic energy

35
Q

what is potential energy

A

related to structure or position for example water at the top of the dam = trapped potential energy (energy of position)

36
Q

what is kinetic energy

A

relates to energy of motion with release of heat

37
Q

water at the bottom of the dam represents ____ ; and the water that cascades over the dam ___

A

lower potential energy

water dissipates to kinetic energy as it moves

38
Q

define biosynthesis

A

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

39
Q

what are energy-releasing and energy conserving processes

A

exergonic

endergonic

coupled recreations

40
Q

what is exergonic

A

any physical or chemical process that releases energy to surroundings (downhill process) with free energy decline

41
Q

what is endergonic

A

chemical reactions that store or absorb energy (uphill process) increase for biologic work

42
Q

what is coupled reactions

A

exergonic drive endergonic

43
Q

what are forms of energy; can each energy form convert or transform to another

A
chemical 
mechanical
heat
light
electrical
nuclear
yes
44
Q

what are two examples of energy conversion

A

photosynthesis

respiration

45
Q

what type of energy process in photosynthesis; what happens

A

endergonic process

plants transfer solar energy to potential energy in carbohydrates lipids and proteins

46
Q

what type of energy process in respiration; what happens

A

exergonic process

stored energy in plants couples to chemical compounds for biologic work

47
Q

what are three forms of biologic work in humans

A

chemical biosynthesis of cellular molecules

mechanical - muscle contraction

transport - transfer of substances among cells

48
Q

what does bioenergetics refer to

A

the flow and exchange of energy within a living system

49
Q

what is an example of potential energy

A

macronutrients before releasing stored energy in metabolism

50
Q

what are two factors that affect the rate of bioenergetics

A

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

51
Q

___speeds up (catalyze) chemical reactions; in some cases can make a chemical reaction millions of times faster

A

enzymes

52
Q

a substrate binds to ___ site of an enzyme and is converted into ___.

A

active site

products

53
Q

once the products leave the active site the enzyme is ready to

A

attach to a new substrate and repeat the process

54
Q

what are some classification of enzymes

A
oxidoreductases 
transferases
hydrolases
lyases
isomerases
ligases
55
Q

what are some examples of specific enzymes (note there are thousands of enzymes in the human body)

A
lipases
amylase
maltase 
trypsin  
lactase 
acetylcholinesterase 
helicase 
DNA polymerase
56
Q

lipases

A

digest fat

57
Q

amylase

A

change starch into sugars (saliva)

58
Q

maltase

A

breaks maltose into glucose (saliva) (potatoes, pasta, beer)

59
Q

trypsin

A

small intestine breaks proteins down

60
Q

lactase

A

small intestine breaks lactose into glucose and galactose

61
Q

acetylcholinesterase

A

breaks down Ach in nerves and muscles

62
Q

helicase

A

unravels DNA

63
Q

DNA polymerase

A

synthesize DNA from deoxyribonucleotides

64
Q

what are the steps in the lock and key mechanism of an enzyme and substrate

A

substrate matches active site of enzyme

enzyme-substrate complex splits to yield product

enzyme now available for interaction with other substrate

65
Q

according to the lock and key mechanism; enzyme turns on when its active site joins in a perfect fit with the

A

substrates active site

66
Q

enzyme substrate lock and key interaction ensures that the

A

correct enzyme matches with its specific substrate to perform a particular function

67
Q

do enzymes all operate at the same rate; what is this called

A

no

turnover number

68
Q

what is the turnover number

A

number of moles of substrate that react to form product per mole of enzyme per unit time

69
Q

what alters enzyme activity

A

pH and temperature

70
Q

enzyme inhibition

A

substances inhibit enzyme activity to slow the reaction rate

71
Q

what are two types of enzyme inhibition

A

competitive inhibition

non-competitive inhibition

72
Q

what is competitive inhibition

A

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

73
Q

what is non competitive inhibition

A

do not resemble target substrate

bind to a non-active site, altering the enzyme structure

74
Q

what is michaelis-menten kinetics

A

in biochemistry this type of kinetics is one of the best known models of enzyme kinetics

75
Q

rate of a reaction is the ____ which is referred to as V

A

speed of a reaction

76
Q

the maximum rate of a reaction is referred to

A

Vmax

77
Q

Km is the ____ at which the enzyme will be running at “half speed”. it is defined as ___

A

concentration of substrate

as the concentration of substrate that stimulates 50% Vmax

78
Q

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

A

Vmax

79
Q

Vmax is influenced by

A

the rate of the enzyme

80
Q

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

A

low to moderate

Km

81
Q

Changes in Km influence enzyme activity as low to moderate substrate levels but do not influence

A

Vmax

82
Q

some enzymes have multiple binding sites for a substrate which may be beneficial because of

A

cooperativity

83
Q

what are examples of cooperativity

A

hemoglobin

SERCA (which is sarcoendoplasmic reticulum Ca2+-ATPase)

84
Q

do enzymes that display cooperativity display michaelis-menten kinetics

A

No

85
Q

in cooperativity is Vmax still the maximal turnover rate of the enzyme

A

yes

86
Q

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”

A

K0.5

87
Q

does the change in K0.5 during cooperativity influence enzyme activity at low to moderate substrate levels but not influence the Vmax?

A

yes

88
Q

in biochemistry ______ is the regulation of an enzyme by binding an effector molecule at a site other then the enzymes active site

A

allosteric regulation (allosteric control)

89
Q

post translational modification (PTM) refers to

A

the covalent and generally enzymatic modification of proteins following protein biosynthesis

90
Q

____ is an example of a covalent modification to an enzyme; may also result in inactive depending on the enzyme

A

phosphorylation

91
Q

what are coenzymes

A

complex nonprotein organic substances that assist enzyme action

92
Q

how do coenzymes assist enzyme action

A

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

93
Q

hydrolysis is

A

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

94
Q

condensation is

A

structural components of nutrients bind together to form more complex molecules and compounds

95
Q

oxidation is

A

reactions that transfer oxygen hydrogen atoms or electrons

96
Q

oxidation always involves electron gain/loss

A

loss

97
Q

loss of electrons in oxidation always occurs with a

A

net gain in valence

98
Q

reduction is

A

any process in which atoms in an element gain electrons with a corresponding net decrease

99
Q

reduction always involves electron gain/loss

A

gain

100
Q

reducing agent is

A

substance that donates or loses electrons as it oxidizes

101
Q

oxidizing agent is

A

substance being reduced or gaining electrons

102
Q

as intensity of exercise increases and oxygen supply (for use) becomes reduced some pyruvate

A

gains 2 hydrogen electrons and becomes reduced to form lactate

103
Q

during recovery when oxygen supply is adequate lactate

A

loses 2 electrons and oxidizes back to pyruvate

104
Q

____ is a key molecule in redox reactions

A

NAD+

105
Q

what are the 4 redox reactions

A

glycolysis
citric acid cycle
electron transport chain
beta oxidation

106
Q

oxidation and reduction reactions constitute the biochemical mechanism that

A

underlies energy metabolism

107
Q

mitochondria remove electrons from hydrogen and eventually

A

pass them to oxygen atoms

which is ATP synthesis occurs during redox reactions

108
Q

where does oxidative phosphorylation occur

A

in the mitochondria

109
Q

what is the cristae

A

the inner membrane is folded to maximize surface area

110
Q

what happens in the matrix

A

krebs or citric acid cycle enzymes which make some ATP and a lot of NADH and FADH2 to power the electron transport chain

111
Q

what does the electron transport chain do

A

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

112
Q

what is the respiratory chain

A

transport of electrons by specific carrier molecules

113
Q

the electron transport chain is the final common pathway in what metabolism

A

aerobic metabolism

114
Q

during the electron transport chain for each pair of hydrogen atoms ____electrons flow down the chain and reduce ____ oxygen atom

A

2 electrons

1 oxygen

115
Q

how does the electron transport chain process end

A

when oxygen accepts two hydrogen electrons and forms water

116
Q

what are two electron carriers

A

NAD and FAD

117
Q

NAD is reduced to ____ during ___ and during ____

A

NADH in glycolisis and citric acid cycle

118
Q

FAD is reduced to FADH2 in the

A

citric acid cycle

119
Q

for every NADH how many ATP are produced

A

3

120
Q

for every FADH2 how many ATP are produced

A

2

121
Q

where does NADH go in the electron transport chain

A

complex 1

122
Q

where does FADH2 go in the electron transport chain

A

complex 2

123
Q

the six forms of energy include

A

chemical mechanical heat light electrical and nuclear

124
Q

energy transfer in humans appear in three forms of biological work

A

chemical mechanical or transport

125
Q

enzyme kinetic properties can be altered by

A

regulatory pathways

126
Q

hydrolysis and condensation reactions form the basis of

A

digestion and synthesis

127
Q

redox reactions provide the basis for the

A

body’s energy transfer processes

128
Q

macronutrient fuel sources

A

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

129
Q

the cells two major energy-transforming activities are

A

extract potential energy from food and conserve it within the ATP bonds

extract and transfer the chemical energy in ATP to power biologic work

130
Q

cells contain only a small quantity of ATP so it must

A

continually be resynthesized

131
Q

ATP levels decrease in skeletal muscle only

A

under extreme exercise conditions

132
Q

the body stores 80-100g of ATP at any time under normal resting conditions this is enough stored energy to power

A

2-3 seconds of maximal exercise

133
Q

how is ATP produced

A

by the citric acid cycle respiratory chain and glycolysis

134
Q

the citric acid cycle and respiratory chain are anaerobic or aerobic

A

aerobic

135
Q

what is used in the citric acid cycle and respiratory chain to produce ATP

A

fatty acids
pyruvate from glucose
some deaminated amino acids

136
Q

glycolysis is anaerobic or aerobic

A

anaerobic

137
Q

what is used in glycolysis to produce ATP

A

phosphocreatine
glucose/glycogen
glycerol
some deaminated amino acids

138
Q

at the beginning of exercise in the untrained state the accumulation of ADP is countered by HEPT +

A

glycolysis

139
Q

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

A

ADP

oxidative phosphorylation

140
Q

what remains elevated after exercise stops, why?

A

oxidative phosphorylation

in order to remove ADP by regenerating PCr

141
Q

6 minutes of high intensity cycling at 90% VO2max leads to

A

big changes in ATP and proportional increases in ADP

142
Q

what are the High energy phosphate transfer

A

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)

143
Q

phosphocreatine is the

A

energy reservoir

144
Q

some energy for ATP resynthesize comes from anaerobic splitting of a

A

phosphate from phosphocreatine

145
Q

cells store approaximalty ___to____X more PCr than ATP

A

4-6times

146
Q

PCr reaches its maximum energy yield in about

A

10seconds

147
Q

____ is impacted following 6 minutes of high intensity cycling at 90% VO2max as a way to buffer changes in ATP

A

phosphocreatine

148
Q

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

A

challenge to ATP homeostasis

149
Q

as intensity of exercise increases and oxygen supply becomes reduced some pyruvate gains 2 hydrogen electrons and becomes ______ to form ___

A

reduced to form lactate

150
Q

during recovery when oxygen supply is adequate lactate loses 2 electrons and ____ back to ___

A

oxidizes back to pyruvate

151
Q

does metabolism and metabolic pathways work one at a time in order

A

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

152
Q

ATP homeostasis is balance of

A

energy utilized by cellular ATPases and energy produced by metabolic pathways

153
Q

at rest ATP utilization = ____ umol ATP/gmuscule/second

A

0.01

154
Q

during exercise ATP utilization = ____ umolATP/ gmuscle/second

A

10

155
Q

the net depletion of ATP in muscle rarely goes below __% because

A

30% because ATP utilization pathways are tightly coupled to ATP metabolic pathways

156
Q

it could be said that ATP utilization or ADP production controls the

A

rate of metabolic ATP production in order to regulate ATP homeostasis

157
Q

ATP homeostasis is regulated by what ratio

A

ATP:ADP

158
Q

what does the term tight coupling mean

A

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

159
Q

a tightly coupled system will have

A

small changes in ATP:ADP ratio because ATP production is tightly coupled with ATP utilization

160
Q

what impact does exercise training have on how quickly metabolic pathways turn on

A

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

161
Q

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

A

PCr ADP AMP and IMP

no much smaller changes

162
Q

why did ADP homeostasis become more tightly regulated following high intensity interval training

A

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

163
Q

glycolysis can power about ___ seconds of contraction

A

30 seconds

164
Q

what are the two phases of glycolysis

A

energy investment phase and energy generation phase

165
Q

if we start with glycogen in glycolysis how many ATP is used in the energy investment stage

A

only 1

166
Q

what are the two forms of carbohydrate breakdown

A

anaerobic (rapid glycolysis)

aerobic (slow glycolysis)

167
Q

what does anaerobic rapid glycolysis result in during carb breakdown

A

results in pyruvate to lactate formation with the release of about 5% of energy within the original glucose molecule

168
Q

what does aerobic slow glycolysis result in during carb breakdown

A

results in pyruvate to acetyl-coA-to-citric acid cycle and electron transport chain of the remaining energy within the original glucose molecule

169
Q

what is glycolysis regulated by

A

concentration of glycolytic enzymes hexokinase, phosphofructokinase and pyruvate kinase

levels of the substrate fructose 1,6-disphosphate

oxygen

170
Q

glycolysis makes

A

pyruvate

171
Q

if pyruvate enters the krebs cycle and there is no pyruvate left to convert in to lactate then

A

lactate will not be produced because lactate will only form when pyruvate concentrations are so high that all of it cannot enter the mitochondria

172
Q

lactate is generated when

A

pyruvate production from glycolysis exceeds the rate of pyruvate entry into the mitochondria

173
Q

when lactate is produced it can alter the cellular pH and the acidity does what

A

impairs excitation contraction coupling processes which leads to muscle fatigue

174
Q

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

A

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

175
Q

in the trained state what is different about the HEPT and glycolysis then in the untrained state during exercise

A

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

176
Q

oxidative phosphorylation is activiated much earlier in the trained state due to

A

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

177
Q

like in the untrained state the trained state oxidative phosphorylation remains elevated after exercise to remove ADP by regenerating PCr but what is different

A

the total ADP content is less in a tightly coupled system so the oxygen debt is paid back faster

178
Q

what are the 5 sources of carbohydrate metabolism

A
muscle glycogen 
glucose
liver glycogen
lactate
CHO ingestion
179
Q

what is glycogenesis

A

glycogen synthesis

surplus glucose forms glycogen in low cellular activity and or with depleted glycogen reserves

180
Q

what is glycogenolysis

A

glycogen breakdown

glycogen reserves break down to produce glucose in high cellular activity with glucose depletion

181
Q

what are key enzymes (where do they occur)

A

hexokinase (step 1)

phosphofuctokinase (step 3)

occurs in the cytoplasm

182
Q

what are reactions that occur in the cytoplasm

A

NAD reduced to NADH + H ( step 6)

substrate phosphorylation (step 7&10)

pyruvate or lactate production

183
Q

what is the net production of ATP in glycolysis when using glucose

A

2 ATP

184
Q

what is the net production of ATP in glycolysis when using glycogen

A

3 ATP

185
Q

for each glucose molecule that is derived from blood glucose that enters glycolysis there is a net total of ____ATP generated

A

2

186
Q

for each glucose molecule that is derived from glycogen molecule that enters glycolysis there is a net total of ___ ATP generated

A

3

187
Q

pyruvate is brought into the mitochondria through the

A

pyruvate dehydrogenase (PDH) enzyme

188
Q

pyruvate dehydrogenase

A

pyruvate + NAD + Coenzyme A —-> acetyl-CoA + CO2 + NADH + H

189
Q

activation of PDH? is promoted by any sudden demands upon the cell signalled by

A

Ca

190
Q

should lactate be viewed as a waste product hy

A

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

191
Q

____ speeds up glycolysis

A

exercise

192
Q

the electron transport chain pumps what

A

protons across inner mitochondrial membrane

193
Q

explain the coupling of electron transport and oxidative phosphorylation

A

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

194
Q

aerobic glycolysis results in __ entering the mitochondria

A

pyruvate

195
Q

what are the key enzymes in the citric acid cycle

A

citrate synthase

succinate dehydrogenase

196
Q

enzymes in the krebs cycle are constant proportion to each other and exercise training can

A

increase mitochondria number which leads to similar increases in all krebs cycle enzymes

197
Q

the electron transport chain represents the final common pathway where electrons extracted from

A

hydrogen pass to oxygen

198
Q

mitochondrial oxygen levels drive the respiratory chain by serving

A

as the final electron acceptor to combine with hydrogen to form water

199
Q

what is oxygens role in energy metabolism

A

serves as the major oxidizing agent in tissues

ensures that energy transfer reactions proceed at appropriate rate

200
Q

aerobic metabolism refers to

A

energy-generating catabolic reactions where oxygen serves as the final electron acceptor in the respiratory chain to combine with hydrogen to form water

201
Q

oxidative phosphorylation synthesizes ATP by

A

transferring electrons from NADH and FADH2 to oxygen

202
Q

more the __% of ATP synthesis takes place in the respiratory chain by oxidative reactions coupled with phosphorylation

A

90%

203
Q

mitochondria remove electrons from hydrogen and eventually pass them to

A

oxygen atoms

204
Q

ATP synthesis occurs during ___ reactions

A

redox

205
Q

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

A

used to synthesise ATP from ADP and Pi

206
Q

what are the two stages of the oxidative phosphorylation

A

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

207
Q

how energy is transferred is known as

A

chemiosmotic hypothesis

208
Q

how does the body harness potential gradients

A

gradients (both energy and concentration)

its the coupling mechanism that binds ADP and a phosphate ion to synthesize ATP

209
Q

what is the net energy transfer from glucose catabolism

A

32 ATP

210
Q

substrate phosphorylation reacting in glycolysis produces how many ATP, the remaining 4 H produced in glycolysis makes how many ATP

A

2

5

211
Q

the 3 H that is used in the pyruvate to acetyl coA reaction makes how many ATP

A

5

212
Q

how many ATP is made in the citric acid cycle (by substrate phosphorylation and by the H)

A

2 (substrate phosphorylation)

15(12 H)

3 (4H)

213
Q

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 ___

A

ADP

o2 consumption in the ETC

214
Q

a reduction in NADH concentration lifts the break on pyruvate oxidation so the mitochondria turns on the krebs cycle to

A

generate a lot more NADH and FADH2

speeds up NAD and FAD regeneration

215
Q

compounds that either inhibit or activate enzymes in the oxidative pathways modulate regulatory control of

A

glycolysis and the citroc acid cycle

216
Q

what serves as enzyme inhibitors

A

ATP and NADH

217
Q

what functions as enzyme activators

A

ADP and NAD

218
Q

cellular ADP concentration exerts the greatest effect on __ what do other modulators include

A

the rate limiting enzymes that control macronutrient energy metabolism

cellular levels of phosphate, cyclic AMP, AMPK, Ca, NAD, citrate and pH

219
Q

what are three specific energy sources for fat catabolism

A

triacylglycerols (stored directly in muscle mitochondria)

circulating triacylglycerol’s
(in lipoprotein complexes)

circulating free fatty acids (from triacylglycerol’s in adipose tissue)

220
Q

complete oxidation of triacylglycerol molecule yields about ___ATP molecules

A

460

221
Q

how does triacylglycerol yield 460 ATP

A

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

222
Q

fat catabolism in adipocytes releases fatty acids into the blood (7 steps)

A

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

223
Q

increase hormone sensate lipase leads to

A

free fatty acid delivery

epinephrine and norepinephrine (catecholamine)
glucagon

growth hormone

224
Q

hormonal release triggered by exercise stimulates

A

adipose tissue lipolysis to further augment FFA delivery to active tissue

225
Q

glycerol catabolism

A

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

226
Q

fatty acid catabolism

A

fatty acids are transformed into acetyl CoA in mitochondria via beta oxidation for entry into the citric acid cycle

227
Q

explain beta oxidation:

once the fatty acyl CoA is transported into the mitochondrial matrix it passes through

A

beta oxidation

228
Q

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

A

2

229
Q

the fatty acyl CoA carbons are removed two at a time to continue forming

A

acetyl CoA and reducing equivalents until totally degraded

230
Q

is it unclear if the same signals (Ca ADP AMP redox state) regulate beta oxidation like they do the other metabolic pathways

A

yes

231
Q

is it likely that substrate availability fatty acyle-CoA NAD and FAD are the dominant activators beta oxidation

A

yes

232
Q

the most effective way to enhance the beta oxidation pathway is to

A

increase mitochondrial content

233
Q

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

A

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

234
Q

citric acid cycle provides the vital link between

A

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

235
Q

fats burn in a carbohydrate flame is a phrase that captures the fact that

A

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

236
Q

in order to burn fats there needs to be some level of

A

aerobic glycolysis

237
Q

what are the major metabolic interconversions while storing potential energy to be accessed later

A

carbohydrates covert to fats by lipogenesis or nonessential amino acids

fats convert to nonessential amino acids

proteins convert to carbohydrates or fats

238
Q

energy allocations progress on a

A

continuum

239
Q

what is the oxygen deficit

A

expresses difference between o2 consumed during exercise and what would have been consume had the steady rate begun from the start

240
Q

how is there a faster increase in VO2 in trained state

A

increase bioenergetics
increase cardiac output (Q)
increase regional blood flow coupled with cellular adaptations

241
Q

when will muscle lactate form

A

when insufficient oxygen is available to fuel oxidative phosphorylation

242
Q

high energy phosphates will buffer ATP concentrations for a period of time during _____ but will eventually not be able to fuel the

A

intense exercise

ATP demand of muscle contractions

243
Q

pulmonary ventilation and lactate versus o2 consumption

A

lactic acid + sodium bicarbonate –> Na lactate + carbonic acid __> water + carbon dioxide

lactic acid + NaHCO3–> Na lactate + H2CO2–> H20 + CO2

244
Q

what is the immediate energy system

A

ATP-PCr

245
Q

what is the short term energy system

A

glycolysis

246
Q

what is the long term energy system

A

aerobic

247
Q

EPOC following exhaustive exercise

A

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