1D: Principles of Bioenergetics & Fuel Molecule Metabolism Flashcards
(251 cards)
1
Q
Endothermic Reactions
A
Require energy, nonspontaneous, positive heat flow (absorbed = feels cold), increase enthalpy, breaking chemical bonds
2
Q
Exothermic Reactions
A
Release energy, can be spontaneous, high entropy, negative heat flow (lost = feels hot), decrease enthalpy, form chemical bonds
3
Q
Free Energy Equation
A
dG = dH - TdS
4
Q
Standard Free Energy Equation
A
dG = -RTlnK
5
Q
dG less than 1
A
K>1, favors products, spontaneous
6
Q
dG equal to 0
A
K=1, at equilibrium
7
Q
dG greater than 1
A
K
8
Q
Nonspontaneous Reaction Criteria
A
\+G = +H, -S \+G = +H, +S (low temp) \+G = -H, -S (high temp)
9
Q
Spontaneous Reaction Criteria
A
- G = +H, +S (high temp)
- G = -H, +S
- G = -H, -S (low temp)
10
Q
Spontaneous Reaction Criteria
A
- G = +H, +S (high temp)
- G = -H, +S
- G = -H, -S (low temp)
11
Q
ATP Hydrolysis
A
ATP + H2O -> ADP + Pi
Exergonic (dG
12
Q
ATP Group Transfer
A
When ATP is depleted during exercise, phosphate is transferred from phosphocreatine to ADP to replenish ATP
13
Q
Oxidation Half Reaction
A
Loses electrons (uses solid)
14
Q
Reduction Half Reaction
A
Gains electrons (produces solid)
15
Q
Soluble Electron Carriers
A
Electrons transferred from one electron carrier to another; energy level decreases; energy is released
16
Q
Ubiquinone (Q)
A
Lipid-soluble electron carrier; reduced to ubiquinol
17
Q
Cytochrome c
A
Water-soluble electron carrier; contains Fe pigment
18
Q
Quinone
A
Lipid-soluble carrier that shuttles electrons between large macromolecular complexes embedded in the membrane
19
Q
Quinone
A
Lipid-soluble carrier that shuttles electrons between large macromolecular complexes embedded in the membrane
20
Q
Flavoproteins
A
Derivatives of riboflavin; FAD and FMN; involves in bioluminescence, photosynthesis, DNA repair, apoptosis
21
Q
Electron Transfer Flavoprotein
A
Function as a specific electron acceptor for primary dehydrogenases
22
Q
Carbohydrate Formula
A
(CH2O)n; deoxy = hydrogen replacing -OH
23
Q
Aldose
A
Sugar with an aldehyde group
24
Q
Ketose
A
Sugar with a ketone group
25
Pyranose
Hexagonal ring
26
Furanose
Pentagonal ring
27
Common Sugars
Glucose, Galactose, Fructose
28
Absolute Configuration
D/L = based on chirality of the carbon atom furthest from the carbonyl group
Alpha/Beta = anomeric configuration
29
Alpha Anomer
Oxygens are cis to each other
30
Beta Anomer
Oxygens are trans to each other
31
Beta Anomer
Oxygens are trans to each other
32
Epimers
Diastereomers; different configuration at one of the chiral carbons
33
Anomers
Stereoisomers; different configuration at the same carbon
34
Hydrolysis of Glycoside Linkage
Done by enzymes (amylase = starch, glycosylase = nucleotide)
35
Hydrolysis of Glycoside Linkage
Done by enzymes (amylase = starch, glycosylase = nucleotide)
36
Monosaccharides
Colorless, water-soluble, crystalline solid
37
Mutarotation
Equilibrium between the alpha and beta anomer
38
Disaccharides
Simple polysaccharides, made via condensation reaction between two monosaccharides
39
Maltose
Glucose + Glucose (1->4 Linkage)
40
Sucrose
Glucose + Fructose (1->2 Linkage)
41
Lactose
Galactose + Glucose (1->4 Linkage)
42
Lactose
Galactose + Glucose (1->4 Linkage)
43
Polysaccharides
Long chains of repeating monosaccharide units connected by glycosidic links; Storage or Structural
44
Storage Polysaccharides
Starch and Glycogen
45
Structural Polysaccharides
Chitin and Cellulose
46
Starch
B 1->4 linkages
47
Cellulose
A 1->4 linkages
48
Cellulose
A 1->4 linkages
49
Glycolysis
Conversion of Glucose into 2 molecules of Pyruvate; produces 4 ATP molecules and 2 NADH; occurs in cytosol
50
Glycolysis Net Products
2 NADH 2 ATP
51
Glycolysis Enzymes
1. Hexokinase
2. Phosphoglucoisomerase
3. PFK
4. Aldolase
5. GAP Dehydrogenase
6. Phosphoglycerate Kinase
7. Phosphoglycerate Mutase
8. Enolase
9. Pyruvate Kinase
52
Hexokinase
Glucose -> G6P
| -ATP
53
Phosphoglucoisomerase
G6P -> F6P
54
PFK
F6P -> F1,6BP
| -ATP
55
Aldolase
F1,6BP -> GAP or G3P
56
GAP Dehydrogenase (x2)
GAP -> 1,3BPG
-Pi
+NADH
57
Phosphoglycerate Kinase (x2)
1,3BPG -> 3PG
| +ATP
58
Phosphoglycerate Mutase (x2)
3PG -> 2PG
59
Enolase (x2)
2PG -> PEP
| +H2O
60
Pyruvate Kinase (x2)
PEP -> Pyruvate
| +ATP
61
Glycolytic Feeder Pathways
Glycogenolysis, Starch Metabolism
| -contribute glucose to the pathway
62
Fermentation
Anaerobic Glycolysis; converts sugars to acids, gases or alcohol; occurs in bacteria, yeast and o2 starved muscle cells
63
Fermentation
Anaerobic Glycolysis; converts sugars to acids, gases or alcohol; occurs in bacteria, yeast and O2 starved muscle cells; regenerates NAD to keep glycolysis going
64
Fermentation
Anaerobic Glycolysis; converts sugars to acids, gases or alcohol; occurs in bacteria, yeast and O2 starved muscle cells; regenerates NAD to keep glycolysis going
65
Fermentation Chemistry
Redox reaction, reduces pyruvate to oxidize NADH into NAD; 1 NAD per Pyruvate
66
Alcoholic Fermentation
Pyruvate reduced to Ethanol
67
Lactic Acid Fermentation
Pyruvate reduced to Lactate
68
Gluconeogenesis
Synthesis of Glucose from non-carbohydrate sources (pyruvate, lactate, glycerol); occurs in the liver
69
Gluconeogenesis Unique Enzymes
Pyruvate Carboxylase
PEP Carboxykinase
G6Pase
70
Pyruvate Carboxylase
Pyruvate -> Oxaloacetate
+HCO3
-ATP
71
PEP Carboxykinase
OAA -> PEP
| -GTP + CO2
72
G6Pase
G6P -> Glucose
+H2O
-Pi
73
G6Pase
G6P -> Glucose
+H2O
-Pi
74
F1,6BP
Activates PFK,
high levels = glycolysis
low levels = gluconeogenesis
75
PPP Oxidative Phase
Generates NADPH
76
PPP Non-oxidative Phase
Generates 5C Sugar (Ribose-5-Phosphate)
77
PPP Non-oxidative Phase
Generates 5C Sugar (Ribose-5-Phosphate)
78
Net Products of Respiration
36 ATP
79
Net Products of Respiration
36 ATP
80
Regulation of Metabolic Pathways
Done through feedback inhibition, isozymes, enzymes concentrations, rapid effect or slow effects
81
Isozymes
Different enzymes that catalyze the same reaction
82
Regulation of Glycolysis
Irreversible steps: Hexokinase, PFK, Pyruvate Kinase
| F2,6BP, AMP
83
F2,6BP
Potent Activator of PFK-1, synthesized when blood sugar is low and glucagon elevates cAMP
84
PEPCK Inhibitors
ADP
85
F1,6BP
Activates PFK,
high levels = glycolysis
low levels = gluconeogenesis
86
Glycogenolysis [Muscle]
Provides G6P for Glycolysis; Muscle lacks G6Pase
87
Glycogenolysis [Liver]
Creates free glucose to be released into the bloodstream for cellular uptake
88
Glycogenolysis Enzymes
Glycogen Phosphorylase
Phosphoglucomutase
Glycogen Debranching Enzyme
89
FBPase Activators
Citrate
90
Glycogenesis Enzymes
```
Hexokinase
Phosphoglucomutase
UDP-Glucose Phosphorylase
Glycogenin
Glycogen Synthase
```
91
Pyruvate Kinase Activators
F1,6BP
92
Glycogenin
Acts as a primer, converting glucose to glycogen; it is a glycosyltransferase
93
Pyruvate Carboxylase Activators
Acetyl CoA
94
Pyruvate Carboxylase Inhibitors
ADP
95
Protein Kinase A
Activated by epinephrine through adenylate cyclase activity; activated by calcium ions + cAMP
Inhibits Glycogen Synthase
96
Insulin
Stimulates glycolysis, glycogenesis, protein anabolism, lipogenesis
97
Glycogenolysis [Muscle]
Provides G6P for Glycolysis; Muscle lacks G6Pase
98
GLUT2
Transports dephosphorylated glucose into the bloodstream
99
Metabolic Control Analysis
Examines how the control of influx and concentrations of metabolites in a metabolic pathway distributed between different enzymes
100
Acetyl-CoA Production
Produced via Pyruvate Dehydrogenase Complex and Pyruvate Formate Lyase
101
Glycogenesis Enzymes
Hexokinase
Phosphoglucomutase
UDP-Glucose Phosphorylase
Glycogenin
102
UDP-Glucose Phosphorylase
Converts G1P to UDP-Glucose, forming pyrophosphate
103
Glycogenin
Acts as a primer, converting glucose to glycogen; it is a glycosyltransferase
104
```
Dihydrolipoyl Dehydrogenase (E3)
(FAD, NAD+)
```
Restores the complex to its initial state producing NADH
105
Glycogen Phosphorylase
Phosphorylation activates; b form -> a form
106
Protein Kinase A
Activated by epinephrine through adenylate cyclase activity; activated by calcium ions + cAMP
Inhibits Glycogen Synthesis
107
Citric Acid Cycle Enzymes
1. Citrate Synthase
2. Aconitase
3. Isocitrate Dehydrogenase
4. Alpha-Ketoglutarate Dehydrogenase
5. Succinyl-CoA Synthetase
6. Succinic Dehydrogenase
7. Fumarase
8. Malate Dehydrogenase
108
Citrate Synthase
Acetyl-CoA + Oxaloacetate -> Citrate + CoA
109
GLUT2
Transports dephosphorylated glucose into the bloodstream
110
Metabolic Control Analysis
Examines how the control of influx and concentrations of metabolites in a metabolic pathway distributed between different enzymes
111
Alpha-Ketoglutarate Dehydrogenase
[NAD]
[CoA]
Alpha-Ketoglutarate -> Succinyl-CoA
+NADH
+CO2
+H
112
Acetyl-CoA Formation Reaction
| [Pyruvate Dehydrogenase Complex]
Pyruvate + CoA + NAD+ --> Acetyl-CoA + NADH + H+ CO2
113
```
Pyruvate Dehydrogenase (E1)
(Thiamine Pyrophosphate [TPP])
```
Attaches Acetyl Group to Sulfur Atom
114
```
Dihydrolipoyl Transacetylase (E2)
(Lipoate, CoA)
```
Transfers Acetyl from Sulfur to CoA
115
```
Dihydrolipoyl Dehydrogenase (E3)
(FAD, NAD+)
```
Restores the complex to its initial state producing NADH
116
Citric Acid Cycle Products [In Order]
Acetyl-CoA + Oxaloacetate -> Citrate -> Isocitrate -> Alpha-Ketoglutarate -> Succinyl-CoA -> Succinate -> Fumarate -> Malate -> Oxaloacetate
117
When is GTP Produced in the CAC?
From the Succinyl-CoA Dehydrogenase reaction
118
Citric Acid Cycle Enzymes
1. Citrate Synthase
2. Aconitase
3. Isocitrate Dehydrogenase
4. Alpha-Ketoglutarate Dehydrogenase
5. Succinyl-CoA Synthetase
6. Succinic Dehydrogenase
7. Fumarase
8. Malate Dehydrogenase
119
Regulation of Pyruvate Dehydrogenase
Activated by Ca, NAD+, CoA
| Inhibited by high levels of Acetyl-CoA, NADH
120
Aconitase
| [H2O]
Citrate -> Isocitrate
121
Isocitrate Dehydrogenase
| [NAD]
Isocitrate -> alpha-ketoglutarate
+NADH
+CO2
122
Alpha-Ketoglutarate Dehydrogenase
[NAD]
[CoA]
Alpha-Ketoglutarate -> Succinyl-CoA
+NADH
+CO2
+H
123
Succinyl-CoA Synthetase
| [GDP + Pi]
Succinyl-CoA -> Succinate
+GTP
+CoA
124
a-Ketoglutarate Dehydrogenase Regulation
Activated by Ca, AMP
| Inhibited by NADH, Succinyl-CoA
125
Net Outcome of Respiration
2 ATP [Glycolysis]
2 NADH [Glycolysis] = 4 ATP
8 NADH [PyDh+CAC] = 24 ATP
2 FADH2 [CAC] = 4 ATP
Total = ~35
126
Characteristics of Lipids
Insoluble in water, soluble in nonpolar organic solves
| i.e. Hydrophobic, Lipophilic
127
Citric Acid Cycle Products [In Order]
Acetyl-CoA + Oxaloacetate -> Citrate -> Isocitrate -> Alpha-Ketoglutarate -> Succinyl-CoA -> Succinate -> Fumarate -> Malate
128
When is GTP Produced in the CAC?
From the Succinyl-CoA Dehydrogenase reaction
129
CAC Mnemonic
Citrate Alone Is Often Kreb's Starting Substrate For Making Oxaloacetate
130
Regulation of Pyruvate Dehydrogenase
Inhibited by high levels of Acetyl-CoA, NADH
131
Sphingophospholipids
Sphingolipids with a phosphodiester bond
132
Sphingomyelins
Contain phosphatidylcholine or phosphatidylethanolamine; component of the myelin sheath
133
Glycosphingolipids, Cerebrosides, Globosides
Sugar moieties attached instead of a phosphate group
Cerebrosides = monosaccharide connected to sphingosine
Globosides = disaccharide
Gangliosides = oligosaccharide (w/ N-acetylneuraminic acid)
134
Waxes
Long chain fatty acids esterified to long chain alcohols; used for protection against evaporation and parasites in plants and animals
135
a-Ketoglutarate Dehydrogenase Regulation
Activated by Ca, AMP
| Inhibited by NADH, Succinyl-CoA
136
Net Outcome of Respiration
2 ATP [Glycolysis]
2 NADH [Glycolysis] = 4 ATP
8 NADH [PyDh+CAC] = 24 ATP
2 FADH2 [CAC] = 4 ATP
Total = ~35
137
Characteristics of Lipids
Insoluble in water, soluble in nonpolar organic solves
| i.e. Hydrophobic, Lipophilic
138
Phospholipids
Amphipathic (hydrophilic head, hydrophobic tail)
139
Phosphodiester Linkage
Links the polar head to the tail; determines the function of the phospholipid
140
Sesquiterpenes
3 Isoprene Units
141
Sphingolipids
Contain a sphingosine backbone
142
Steroid Hormones
Have high affinity receptors, work at low concentrations, affect gene expression & metabolism; derived from cholesterol
Glucocorticoids [Cortisol], Mineralocorticoids [Aldosterone], Estrogen, Progesterone, Testerone
143
Sphingomyelins
Contain phosphatidylcholine or phosphatidylethanolamine; component of the myelin sheath
144
Prostaglandins
Autocrine & Paracrine Hormones that regulate cAMP levels; affect muscle contraction, body temperature, sleep-wake cycle and pain
145
Waxes
Long chain fatty acids esterified to long chain alcohols; used for protection against evaporation and parasites in plants and animals
146
Vitamin D [Cholecalciferol]
Metabolized to calcitriol; regulates calcium and phosphorus homeostasis; promotes bone formation; deficiency = rickets
147
Vitamin E [Tocopherols]
Biological antioxidants, destroy free radicals and prevent oxidative damage
148
Vitamin K [Phylloquinone & Menaquinone]
Formation of prothrombin (clotting factor)
149
Diterpene
4 Isoprene Units
150
Triterpene
6 Isoprene Units
151
Adipocytes
Animal cells that are used for storage of large triacylglycerol deposits
152
Saponification
The ester hydrolysis of triacylglycerols using a strong base
153
Lipase (Digestion)
Breaks down Triacylglycerols to fatty acids and monoglycerides through hydrolysis
154
Emulsifcation
Breaks down fat globules into emulsion droplets; increases the surface area for digestion
155
Colipase
A protein that binds to lipase at the surface of the emulsion droplets
156
Oxidation of Fatty Acids
Occurs in the Matrix of the Mitochondria; Ester Hydrolysis in the Cytosol
157
Vitamin E [Tocopherols]
Biological antioxidants, destroy free radicals and prevent oxidative damage
158
Vitamin K [Phylloquinone & Menaquinone]
Formation of prothrombin (clotting factor)
159
Why are triacylglycerols the preferred form of energy storage?
They are reduced and anhydrous which allow them to have a greater caloric yield; allows survival for about several weeks
They are not hydrated by the body and do not carry additional weight
160
Triacylglycerols
One glycerol attached to 3 fatty acids by ester bonds
161
Lipid Mobilization
Adipocytes -> Hormone-Sensitive Lipase
| Lipoproteins -> Lipoprotein Lipase
162
Saponification
The ester hydrolysis of triacylglycerols using a strong base
163
Lipase
Breaks down Triacylglycerols to fatty acids and monoglycerides through hydrolysis
164
Emulsifcation
Breaks down fat globules into emulsion droplets; increases the surface area for digestion
165
Colipase
A protein that binds to lipase at the surface of the emulsion droplets
166
Chylomicrons
Packaged groups of lipoprotein particles that are transported into enterocytes
167
Apoproteins
Control interactions between lipoproteins
168
Cholesterol Metabolism
Obtained through dietary sources or de novo synthesis in the liver
169
Enzyme of Cholesterol Biosynthesis
HMG-CoA Reductase
170
Short Chain Fatty Acids
Absorbed across the intestine into the blood
171
CETP Enzyme
Catalyzes transition of IDL to LDL by transferring cholesteryl esters from HDL
172
Lipid Mobilization
Adipocytes -> Hormone-Sensitive Lipase
| Lipoproteins -> Lipoprotein Lipase
173
Where are fatty acids synthesized?
In the cytoplasm from Acetyl-CoA transported out of the mitochondria
174
Chylomicrons
Transport mechanism for dietary TAG molecules and are transported via lymphatic system
175
Where are fatty acids oxidized?
In the mitochondria following transport by carnitine shuttle
176
Acetyl-CoA Shuttling
Citrate is shuttled across the mitochondrial membrane into the cytosol and is split by citrate lyase; Oxaloacetate is then returned to to the mitochondria to continue shuttling Acetyl-CoA
177
HDL
Reverse transport of cholesterol
178
Fatty Acid Synthase
Adds group to ACP and continuously extends the chain using NADPH
179
Cholesterol Metabolism
Obtained through dietary sources or de novo synthesis in the liver
180
Enzyme of Cholesterol Biosynthesis
HMG-CoA Reductase
181
LCAT Enzyme
Catalyzes formation of cholesteryl esters for transport with HDL
182
CETP Enzyme
Catalyzes transition of IDL to LDL by transferring cholesteryl esters from HDL
183
Process of Fatty Acid Synthesis
Activation -> Bond Formation -> Reduction -> Dehydration -> Reduction
-Repeated 8 times to form palmitic acid-
184
Carnitine Acyltransferase II
Converts Acylcarnitine back to Acyl-CoA
185
Beta-Oxidation Enzymes (Even)
1. Fatty Acyl-CoA Dehydrogenase
2. Enoyl-CoA Hydratase
3. Thiolase
186
Where are fatty acids oxidized?
In the mitochondria following transport by carnitine shuttle
187
Beta-Oxidation Enzymes (Monounsaturated)
1. Enoyl-CoA Isomerase
2. Fatty Acyl-CoA Dehydrogenase
3. Enoyl-CoA Hydratase
4. Thiolase
188
Beta-Oxidation Enzymes (Polyunsaturated)
1. Dienoyl-CoA Reductase
| 2. Enoyl-CoA Isomerase
189
Ketone Bodies
Acetoacetate, B-Hydroxybutyrate
190
Ketogenesis
Occurs in the MTC of Liver Cells when excess Acetyl-CoA accumulates; ketone bodies are used for energy
191
Fatty Acid Entry
Involves Carnitine Acyltransferase I; 2-12 Carbons diffuse into MTC, 14-20 carbons utilize Carnitine Shuttle
192
Carnitine Shuttle Enzymes
Carnitine Palmitoyltransferase I
Carnitine Acylcarnitine Translocase
Carnitine Acyltransferase II
193
HMG-CoA Lyase
HMG-CoA -> Acetoacetate -> B-Hydroxybutyrate
194
Ketolysis
Regenerates Acetyl-CoA for use as an energy source in peripheral tissues
195
Carnitine Acyltransferase II
Converts Acylcarnitine back to Acyl-CoA
196
Ketolysis in the Brain
Brain begins to use ketone bodies and derive up to two-thirds of its energy during prolonged starvation; Ketones are metabolized to Acetyl-CoA, Pyruvate Dehydrogenase is inhibited in the brain
197
Beta-Oxidation Enzymes (Odd)
1. Propionyl-CoA Carboxylase
| 2. Methylmalonyl-CoA Mutase
198
Beta-Oxidation Enzymes (Monounsaturated)
Enoyl-CoA Isomerase
199
Beta-Oxidation Enzymes (Polyunsaturated)
Dienoyl-CoA Reductase
200
Non-Template Synthesis of Lipids
DHAP - > Phosphatidic Acid -> Diglyceride [+Acyl CoA] -> Triglyceride
201
Non-Template Synthesis of Polysaccharides
Hexokinase -> Phosphoglucomutase -> G1P UDP Transferase -> Glycogen Synthase
202
Ketogenesis Enzymes
HMG-CoA Synthase
| HMG-CoA Lyase
203
Pyruvate Dehydrogenase Phosphotase
Activates PDH when ADP levels are high
204
Electron Transport Chain
Takes place on the matrix-facing surface of the inner mitochondrial membrane; creates a proton gradient that pumps protons into the ATP synthase in order to produce ATP
205
Complex I
[NADH-CoQ Oxidoreductase]
(4 Protons)
Transfers electrons from NADH -> FMN -> CoQ forming CoQH2
206
Complex II
[Succinate-CoQ Oxidoreductase]
(No Protons)
Transfers electrons from Succinate -> FAD -> CoQ forming CoQH2
207
Ketolysis in the Brain
Brain begins to use ketone bodies and derive up to two-thirds of its energy during prolonged starvation; Ketones are metabolized to Acetyl-CoA, Pyruvate Dehydrogenase is inhibited
208
Complex IV
[Cytochrome c oxidase]
(2 Protons)
Transfers electrons in the form of hydride ions from Cyt c to Oxygen forming Water
209
Transamination/Deamination
Loss of an amino acids amino group that allows the carbon skeleton to be used for energy
210
Malate-Aspartate Shuttle
Electrons transferred from NADH to Oxaloacetate, forming malate which crosses the inner mitochondrial membrane and transfers electrons to NAD+
211
Non-Template Synthesis of Lipids
DHAP - > Phosphatidic Acid -> Diglyceride [+Acyl CoA] -> Triglyceride
212
Flavoproteins
Function as specific electron acceptors for dehydrogenases
213
Cytochromes
Water soluble electron carries that contain iron pigments
214
Pyruvate Dehydrogenase Phosphotase
Activates PDH when ADP levels are high
215
Electron Transport Chain
Takes place on the matrix-facing surface of the inner mitochondrial membrane; creates a proton gradient that pumps protons into the ATP synthase in order to produce ATP
216
Chemiosmotic Coupling
Electron transfer is coupled to ATP synthesis via the proton electrochemical gradient
217
Complex II
[Succinate-CoQ Oxidoreductase]
(No Protons)
Transfers electrons from Succinate -> FAD -> CoQ forming CoQH2
218
Complex III
[CoQH2-cytochrome c Oxidoreductase]
(4 Protons)
Transfers electrons from CoQH2 -> Heme forming Cyt c
219
Complex IV
[Cytochrome c oxidase]
(2 Protons)
Transfers electrons in the form of hydride ions from Cyt c to Oxygen forming Water
220
F1 Portion of ATP Synthase
Uses energy released by the gradient to phosphorylate ADP into ATP
221
Malate-Aspartate Shuttle
Electrons transferred from NADH to Oxaloacetate, forming malate which crosses the inner mitochondrial membrane and transfers electrons to NAD+
222
NADPH
Reducing Agent that drives anabolic reactions
223
Flavoproteins
Function as specific electron acceptors for dehydrogenases
224
Cytochromes
Water soluble electron carries that contain iron pigments
225
Proton-Motive Force
Electrochemical gradient generated by the ETC across the inner mitochondrial membrane
226
MTC Intermembrane Space
Higher concentration of protons than the matrix; stores energy
227
Hormones that Regulate Metabolism
Insulin, Glucagon, Glucocorticoids (Cortisol), Catecholamines (Epinephrine and Norepinephrine), Thyroid Hormones
228
Uncoupling Reagents
Block oxidative phosphorylation by dissipating the electrochemical gradient
229
Glucagon Effects on Metabolism
- Increases rate of catabolic metabolism
- Increases blood glucose by stimulating gluconeogenesis, glycogenolysis
- Secreted by alpha cells of pancreas
230
Glucocorticoids Effects on Metabolism
Increase blood glucose in response to stress by mobilizing fat stores and inhibiting glucose uptake
-Increases the impact of glucagon and catecholamines
231
Catecholamines Effects on Metabolism
| [Epinephrine and Norepinephrine]
Promotes glycogenolysis and increases basal metabolic rate through their sympathetic nervous system activity
232
Energetic Yield
- Glycolysis
- PDH
- CAC
Glycolysis [2 NADH + 2 ATP]
PDH [2 NADH]
CAC [6 NADH, 2 FADH2, 2 GTP]
233
NADH ATP Yield
2.5 ATP per NADH
234
FADH2 ATP Yield
1.5 ATP per NADH
235
Optimal ATP yield per Glucose
30-32 ATP
236
Postprandial State
Well fed, insulin secretion is high and anabolic metabolism is high
237
Postabsorptive State
Fasting, insulin secretion decreases while glucagon and catecholamine secretion increases; transition to catabolic metabolism
238
Hormones that Regulate Metabolism
Insulin, Glucagon, Glucocorticoids (Cortisol), Catecholamines, Thyroid Hormones
239
Brain & Nervous Tissue Metabolism
Consumes glucose mostly but in prolonged fasting, ketone bodies are used.
240
Glucagon Effects on Metabolism
- Increases rate of catabolic metabolism
- Increases blood glucose by stimulating gluconeogenesis, glycogenolysis
- Secreted by alpha cells of pancreas
241
Glucocorticoids Effects on Metabolism
Increase blood glucose in response to stress by mobilizing fat stores and inhibiting glucose uptake
-Increases the impact of glucagon and catecholamines
242
Catecholamines Effects on Metabolism
| [Epinephrine and Norepinephrine]
Promotes glycogenolysis and increases basal metabolic rate through their sympathetic nervous system activity
243
Thyroid Hormones
| [T3 & T4]
Modulates the impact of other metabolic hormones and have a direct impact on basal metabolic rate
-T3 is more potent than T4
244
Liver Metabolism
Responsible for maintenance of blood glucose levels by glycogenolysis and gluconeogenesis in response to pancreatic hormone activity; also processes lipids and cholesterol, bile, urea and toxins
245
Adipose Tissue Metabolism
Stores lipids under the influence of insulin and releases them under the influence of epinephrine
246
Skeletal Muscle Metabolism [Resting]
Conserves carbohydrates in glycogen stores and uses free fatty acids in the blood stream
247
Skeletal Muscle Metabolism [Active]
Anaerobic Metabolism, OXPHOS, Direct phosphorylation from creatine phosphate or beta oxidation
248
Cori Cycle
Lactate -> Gluconeogenesis -> Glucose
| Between Liver & Muscle
249
Cardiac Muscle Metabolism
Uses fatty acid oxidation, uses creatine phosphate
250
Brain & Nervous Tissue Metabolism
Consumes glucose mostly but in prolonged fasting, ketone bodies are used.
251
Hormones that regulate body mass
Leptin, Ghrelin & Orexin
