1D: Principles of Bioenergetics & Fuel Molecule Metabolism Flashcards Preview

MCAT > 1D: Principles of Bioenergetics & Fuel Molecule Metabolism > Flashcards

Flashcards in 1D: Principles of Bioenergetics & Fuel Molecule Metabolism Deck (251):
1

Endothermic Reactions

Require energy, nonspontaneous, positive heat flow (absorbed = feels cold), increase enthalpy, breaking chemical bonds

2

Exothermic Reactions

Release energy, can be spontaneous, high entropy, negative heat flow (lost = feels hot), decrease enthalpy, form chemical bonds

3

Free Energy Equation

dG = dH - TdS

4

Standard Free Energy Equation

dG = -RTlnK

5

dG less than 1

K>1, favors products, spontaneous

6

dG equal to 0

K=1, at equilibrium

7

dG greater than 1

K

8

Nonspontaneous Reaction Criteria

+G = +H, -S
+G = +H, +S (low temp)
+G = -H, -S (high temp)

9

Spontaneous Reaction Criteria

-G = +H, +S (high temp)
-G = -H, +S
-G = -H, -S (low temp)

10

Spontaneous Reaction Criteria

-G = +H, +S (high temp)
-G = -H, +S
-G = -H, -S (low temp)

11

ATP Hydrolysis

ATP + H2O -> ADP + Pi
Exergonic (dG

12

ATP Group Transfer

When ATP is depleted during exercise, phosphate is transferred from phosphocreatine to ADP to replenish ATP

13

Oxidation Half Reaction

Loses electrons (uses solid)

14

Reduction Half Reaction

Gains electrons (produces solid)

15

Soluble Electron Carriers

Electrons transferred from one electron carrier to another; energy level decreases; energy is released

16

Ubiquinone (Q)

Lipid-soluble electron carrier; reduced to ubiquinol

17

Cytochrome c

Water-soluble electron carrier; contains Fe pigment

18

Quinone

Lipid-soluble carrier that shuttles electrons between large macromolecular complexes embedded in the membrane

19

Quinone

Lipid-soluble carrier that shuttles electrons between large macromolecular complexes embedded in the membrane

20

Flavoproteins

Derivatives of riboflavin; FAD and FMN; involves in bioluminescence, photosynthesis, DNA repair, apoptosis

21

Electron Transfer Flavoprotein

Function as a specific electron acceptor for primary dehydrogenases

22

Carbohydrate Formula

(CH2O)n; deoxy = hydrogen replacing -OH

23

Aldose

Sugar with an aldehyde group

24

Ketose

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