quiz 2.2 glyco, gluconeo, TCA Flashcards
(183 cards)
1
Q
how many rxns sa glycolysis
A
10
2
Q
ano phases ng glycosis
A
energy-investing/preparatory
pay-off phase
3
Q
the energy-investing phase involves which rxns
A
first 5
4
Q
in the energy-investing phase, glucose results to
A
2 moles of glyceraldehyde-3-PO4
5
Q
the first priming rxn of glycolysis
A
phosphorylation of glucose
6
Q
in the first step, glucose is irreversibly phosphorylated to _________ by the enzyme _____
A
gulocse-6-PO4
hexokinase
7
Q
where is gluc-6-PO4 trapped
A
cytsol
8
Q
these isoenzymes of hexokinase can phosphorylate other hexoses aside from glucose
A
hexokinase 1 2 3
9
Q
hexokinase isoenzyme with low Km thus high affinity for glucose
A
hexokinase 1 2 3
10
Q
the predominant isoenzyme of hexokinase in the liver and pacnreas
A
hexokinase 4 (glucokinase)
11
Q
this isoenzyme becomes functional only during periods of high level of glucose
A
glucokinase
12
Q
gluckinase has ____ kM thus requiring _____
A
higher
higher
13
Q
where is glucokinase found
A
parenchymal cells in liver
beta cells in pancreas
14
Q
which enzyme is inhibited by gluc-6-PO4
A
hexokinase
15
Q
2nd step of the glycolysis pathway
A
isomerization of gluc-6-PO4
16
Q
in the 2nd step, gluc-6-PO4 is isomerized to _____ by
A
fructose-6-PO4
phosphoglucose isomerase
17
Q
third step of glycolysis
A
phophorylation of fruc-6-PO4
18
Q
in the 3rd step, fruc-6-PO4 is phosphorylated to ________ by _______
A
fructose-1,6-bisphosphate
phosphofructokinase (PFK-1)
19
Q
the rate limiting step, commited step and most important point in glycolysis
A
phosphorylation of fruc-6-PO4 to fruc-1,6-bisPO4
20
Q
what is the rate limiting enzyme
A
PFK-1
21
Q
what are the shits that control the activity of PFK-1
A
energy w/in cell
regulatory substrates
22
Q
___________ of ATP in the cell allosterically inhibits PFK-1
A
elevated levels
23
Q
__________________, signaling depletion of the cell’s energy stores, allosterically activates PFK-1
A
high conc of AMP
24
Q
an intermediate of the TCA cycle that inhibits PFK-1
A
citrate
25
the most potent allosteric activator of PFK-1 that can oppose inhibition by high levels of ATP
fructose-2,6-bisPO4
26
fructose-2,6-bisPO4 formation is catalyzed by
PFK-2
27
PFK-2 is a bifunctional enzyme that has what activities
kinase and phosphatase acivity
28
in the liver, which PFK-2 domain is active if dephosphorylated
kinase
29
which domain of PFK2 catalyzes fruc-2,6-bisPO4 to fruc-6-PO4
phosphatase
30
which domain of PFK2 catalyzes fruc-6-PO4 to fruc-2,6-bisPO4
kinase
31
acts as an intracellular signaling indicating that glucose is abundant
fruc-2,6-bisPO4
32
after a well-fed state, what cause an increase in fruc-2,6-bisPO4
dec. glucagon
| elev. insulin
33
in the fasted state, PFK-2 is ____________ there it is rendered _______
phosphorylated
| inactivated
34
4th step in glycolysis
cleavage of fruc-1,6-bisPO4 to DHAP and glyceraldehyde-3-PO4
35
in the 4th step, fuctose-1,6-bisPO4 is cleaved to __________ by ________
dihydroxyacetone and glyceraldehyde-3-PO4
| aldolase
36
5th step of glycolysis/last step of the energy-investing phase
isomerization of DHAP
37
end product after 5th step of glycolysis
2 moles of glyceraldehyde-3-phosphate
38
in the 5th step, DHAP is interconverted to _______ by ________
glyceraldehyde-3-PO4
| triose phosphate isomerase
39
this phase includes the energy-conserving phosphorylation steps in which some of the chemical energy of the glucose molecule of conserved in the form of ATP and NADH
pay-off phase
40
in the pay-off phase, how many molecules of ATP are formed in the substrate-level phosphorylation per glucose molecule metabolized
2
41
this is the first redox rxn of glycolysis
6th step
42
6th step of glycolysis
oxidation of glyceraldehyde-3-PO4
43
what happens sa first redox rxn ng glycolysis
glyceraldehyde-3-PO4 is conerted to 1,3-bisphosphoglycerate by glyceraldehyde-3-PO4 dehydrogenase
44
in the 6th step, glyceraldeyhde-3-PO4 is converted to _______ by ____
1,3-bisphophoglycertae
| glyceraldehyde-3-PO4 dehydrogenase
45
which part of 1,3-BPG conserves the free energy produced by the oxidation
the phosphate group @ C1
46
the NADH produced during 6th step must be
reoxidized back to NAD to replenish its limited supply
47
2 major mechanisms of oxidizing NADH
coversion pf pyruvate to lactate via LDH
| oxidation of NADH via ETC
48
2 substrate shuttles that transport into the mitochondrial matrix
glycerophosphate n
| malate-aspartate
49
how many ATPs are formed from each cytosolic NADH pxidized in the glycerophosphate shuttle
2
50
in this shuttle, two electrons are transferred from NADH to DHAP by cytosolic glyceraldehyde-3-PO4 dehydrogenase
glycerophosphate shuttle
51
in this shuttle, two electrons are transferred from NADH to oxaloacetate by cytosolic malate dehydrogenase
malate-aspartate shuttle
52
how many ATPs are formed from each cytosolic NADH pxidized in the malate-aspatate shuttle
3
53
oxaloacetate cannot enter the mitochondria therefore it is converted to
malate
54
in RBCs, some 1,3-BPG are converted to _________ by _____________
2,3-BPG
| bisphosphoglycerate mutase
55
in which shunt is 2,3-BPG formed
rapoport-luebering pathway
56
an intermediate formed from 2,3-BPG
3-phosphoglycerate
57
7th step in glycolysis
synthesis of 3-phosphoglycerate, producing ATP
58
in the 7th step, 1,3-BPG is converted to ________ by _______
3-phosphoglycerate
| phosphoglycerate kinase
59
in the 7th step, what specifically is used to form ATP
the high-energy phosphate group of 1,3-BPG
60
formation of ATP in the 7th step is via _____________ phosphorylation, where in the needed energy comes from a substrate not the ETC
substrate-level
61
8th step in glycolysis
shift of the phosphate group
62
in the 8th step, 3-phosphoglycerate is converted to _______ by __________
2-phosphoglycerate
| phosphoglycerate mutase
63
9th step of glycolysis
dehydration of 2-phosphoglycerate
64
in the 9th step, dehydrtion of 2-phosphoglycerate to ____________ is catalyzed by ________________
phosphoenolpyruvate
| enolase
65
10th step of glycolysis
formation of pyruvate, producing ATP
66
what are the 2 ATP producing steps in glycolysis
7
| 10
67
in the 10th step, PEP is converted to ______ by __________
pyruvate
| pyruvate kinase
68
in the 10th step, what specifically is used to form ATP
high enery enol phosphate
69
what are the three irreversible steps in glycolysis
1
3
10
70
puryvate kinase is activated by what
fruc-1,6-bisphosphate-
71
pyruvate kinase is inactivated when
fasted state
72
pyruvate kinase in the liver is inactivated how
phosphorylation by a cAMP-dependent protein kkinase
73
pyruvate is converted to __________ by _______________
lactate
| LDH
74
effect of insulin on glucokinase, PFK and PK
increased synthesis
75
effect of glucagon on glucokinase, PFK and PK
decreased sythensis
76
pyruvate is converted to acetyl CoA by
pyruvate dehydrogenase
77
pyruvate is converted to _____________ by pyruvate dehydrogenase
acetyl CoA
78
pyruvate is converted to oxaloacetate by
pyruvate carboxylase
79
pryvaute is converted to ____ by pyruvate carboxylase
oxaloacetate
80
pyruvate is converted to alanine by
alanine amino transferase using coenzyme PPP
81
the final common pathway for the oxidation of the major macromolecules
TCA
82
resulting product of TCA
acetyl CoA
83
the step that provides the substrate for the TCA
oxidative decarboxylation of pyruvate by PDH complex
84
3 components enzymes of the PDH complex
E1 2 3
85
E1 requires
thiamine pyrophosphate
86
E2 requires
lipoic acid and coenzyme A
87
E3 requires
FAD and NAD
88
E1 aka
pyruvate decarboxylase/dehydrogenase
89
E2 aka
dihydrolipoyl transacetylase
90
E3 aka
dihydrolipoyl dehydrogenase
91
the 2 regulartory enzymes in the PDH complex
PDH kinase
| PDH phosphatase
92
in pyruvate decarboxylaton, pyruvate is carboxylased to
hydroxyethyl derivative bound to TPP
93
in pyruvate decarboxylation, the hydroxyethyl intermediate is tranferred to
disulfide form of lipoic acid bound to E1
94
the acetyl group bound as a thioester to the side chain of lipoid acid i tranferred to
coenzyme A
95
the sulfhydyl form of lipoic acid is oxidized by ______ leading to the regen of ozidized lipoic acid
FAD-dependent E3
96
FADH2 on E3 is reoxidized to ____ and NAD is reduced to ______
FAD
| NADH and H
97
cAMP-independent PDH kinase ________ and _______ E1
phosphorylates and inactivates
98
PDH phosphatase _____ and ____ E1
dephosphorylates and activates
99
PDH is also regulated via inhibition by its products _____
actyl CoA and NADH
100
pyruvates inhibits which PDH domain
PDH kinase
101
calcium activates which PDH domain
PDH phosphatase
102
2nd step in TCA
isomerization of citrate
103
formation of cirate is caused by
citrate synthase
104
citrate is synthesized from
acetyl CoA and oxaloacetate
105
inhibitor of citrate synthase
citrate
106
this is the rate-limiting enzyme of glycolysis
PFK-1
107
in the 2nd step of TCA, isomerization of citrate to ______ is catalyzed by
isocitrate
| aconitase
108
3rd step of TCA
oxidative carboxylation of isocitrate
109
the 3rd step of TCA yields the first ________ and _______
NADH
| CO2
110
isocitrate dehydrogenase is activated and inactivated respectively by ____ and ______
ADP (low energy signal)
| ATP (high energy signal)
111
4th TCA step
oxidative decarboxylation of alpha ketoglurate
112
in the 4th step, alpha ketoglutarate is converted to ___ by _____
succinyl CoA
| alpha-ketoglurate dehydrogenase complex
113
the 4th step of TCA yields the ______ and _______
second NADH and CO2
114
inhibitors of the alpha-glutarate dehydrogenase complex
NADH and succinyl CoA
115
5th step in TCA
cleavage of succinyl CoA
116
in the 5th step of TCA, succinyl CoA is cleaved to ___ by ____
succinate
| succinyl CoA synthetase/succinate thiokinase
117
the cleaveof succinylCOA is coupled with the phosphorylation of _______________ to ______________
GDP to GTP
| another substrate level phosphrylation
118
6th step in TCA
oxidation of succinate
119
in the 6th step, oxidation of succinate to _____ is catalyzed by _____
fumarate
| succinate dehydrogenase
120
only enzyme of the TCAe mbedded in the inner mitochondrial membrane
succinate deydrogenase
121
7th step of TCA
hydration of fumarate
122
in the 7th step, fumarate is hydrated to _____ in a freely reversible rxn catalyzed by _____
malate
| fumarase [hydratase]
123
8th step of TCA
oxidation of malate
124
in the 8th step of TCA, oxidation of malate to _____ is catalyzed by ___
OXAA
| malate dehydrogenase
125
the 8th step of TCA yields the ____ and _____
third and last NADH and CO2
126
one cycle of TCA produces how many ATPs
12
127
each NADH produced in the TCA corresponds to how many ATPs
3
128
each FADH2 produced in the TCA corresponds to how many ATPs
2
129
bakit 12 ATPs ang formed sa TCA
3 NADH
1 FADH2
1 GTP
130
net ATP produced in the complete aerobic oxidation of glucose via glycolysis, PDH complex rxn, TCA cycle and oxidative phosphorylation in the ETC
36-38 ATPs
131
kelan 36 ang ATPs yield
kpaag glycerophosphate shuttle ang ginamit
132
kelan 38 ATPs yield
kpag malate-aspartate shuttle ang ginamit
133
three most important enzymes when regulated TCA cycle
citrate synthase
isocitrate dehydrogenase
alpha-ketoglutarate dehydrogenase complex
134
what is common in the 3 most important enzymes for TCA cycle regulation
highly negative Gibbs (Gibbs nga ba ung deltaGo? ahaha)
135
what are the substrates for citrate synthase
acetylCoA and OXAA
136
when [NADH/NAD] is high, the concentration of OXAA is low, therefore slowing which step of TCA cycle
first step
137
what inhibits accumulation of isocitrate, alpha-ketoglutarate, malate oxidation in teh TCA cycle
high [NADH/NAD]
138
examples of 'product accumulation inhibits all 3 limiting steps of the TCA cycle'
inhibition of:
succinylCoA to alpha keto dehyro
citrate to itrate synthase
ATP to citrate synthase and isocitrate dehydro
139
what is an activator of citrate synthase
ADP
140
most important anaplerotic rxn in mammalian liver and kidney
reversible carboxylation of pyruvate by CO2 to form OXAA catalyzed by pyruvate carboxylase
141
when the TCA is deficient in OXAA or any other intermediate, pyruvated is carboxylated produce __________
more OXAA
142
what is the positive allosteric modulator of pyruvate carboxylase
acetylCoA
143
in the absence of carbo source in ______ hrs, glycogen can provide
10-18
144
in prolongeed fasting, ilan carbo galing kidney
40%
145
in overnight fasting, ilan carbo galing kidney
10%
146
substrates for gluconeogenesis
lactate
glucogenic AAs
glycerol
147
cycle where exercising muscle cells release lactate then turned into glucose then into lctate again and then release into the blood
Cori cycle/lactic acid cycle
148
major source of glucose during fast
glucogenic amino acids
149
________ is a glucogenic AA converted to glucose via _______ rxn
alanine
| trasamination
150
show rxns how glycerol is a source of glucose
glycerol > glycerol-3-PO4 > DHAP
151
what catalyzes glycerol > glycerol 3-PO4
glycerol kinase
152
what catalyzes glycerol-3-PO4 > DHAP
glycerol-3-PO4 dehydrogenasw
153
how many steps sa guconeogenesis
7
154
how many glucone0genesis rxns are irreversible
3
155
initial substrate for gluconeogensis
pyruvate
156
1st unique step in gluconeo
carboxylation of pyruvate
157
in gluceo neo 1st unique step, pyruvate is carboxylated to _____ by _____ then further to _______ by _____
OXAA
pyruvate carboxylase
PEP
PEP carboxylase
158
di makapasok ang OXAA sa cytosol kaya kailanangang
gawing malate
159
2nd unique step in gluconeo
decarboxylation of cytosolic oxaloacetate
160
in the 2nd unique step of gluconeo, OXAA is decarboxylated and phosphorylated to ________ by _________
PEP
| PEP-carboxykinase
161
after the 2nd unique step of gluconeo, PEP follows the reverse direction of glycolysis until ____________-- is formed
fructose-1,6-bisPO4
162
3rd unique step of gluconeo
dephosphorylation of fructose-1,6-bisPO4
163
the 3rd unique step of gluconeogenesis bypasses what
irreversible PFK-1
164
hydrolysis of fructose-1,6-bisPO4 to ________ is catalyzwed by
fructose-6-phosphate
| fructose 1,6-bisPO4ase
165
increased level of AMP causes what to F1,6BPase and PFK1
inhib. F1,6BPase
activ. PFK1
therefore dec. gluconeo inc. glycolysis
166
an allosteric effector of F1,6BP influenced by insulin to glucagon ratio
F26BP
167
when is F26BP not made
high glucagon
168
synthesis of F16BPase is induced during
fasting
169
4th unique step of gluconeogenesis
dephosphorylation of glucose-6-phosphate
170
in the 4th unique step of gluconeo, G6P is hydrolysed by
glucose-6-phosphatase
171
the 4th unique step of gluconeo bypasses what
irreversible hexokinase/glucokinase rxn
172
what are the only organs that release free glucose from glucose-6-phosphate
liver and kidney
173
G6PO4 is transported from liver to ____
cytosol
174
what transports G6PO4 from liver to cytosol
G6PO4 translocase
175
recipe for gluconeogenesis
```
2 pyru
2 CO2
6 high energy bonds
7 reversible glycolysis rxn
4 irrev. enzymes
```
176
what are the 4 irreversible enzymes ng gluconeogenesis
pyruvate carboxylase
PEPCK
F16BPase
G6pase
177
how many moles of pyruvate is needed to make one glucose
2
178
how mnay moles of ATP are hydrolyzed when making glucose from pyruvate
2
179
in gluconeogensesis, glucagon lowers which shit
F26BPO4
180
glucagon lowering F26BPO4 results to
activatio of F16BPO4
| inhibition of PFK1
181
what does glucagon inactivate thru its cAMP-dependent protein kinase activity
hepatic PK
182
glucagon increases the transcription of the gene for what
PEPCK
183
acetyl CoA during fasting can divert pyruvate to ____ and away from the ____
gluconeo
| TCA cycle
