Biochemistry : Metabolism

Front 1

Palmitic acid

Back 1

CH₃(CH₂)₁₄COOH

16:0

106 ATP from degradation

Front 2

Stearic Acid

Back 2

CH₃(CH₂)₁₆COOH

18:0

120 ATP from degradation

Front 3

Palmitoleic acid

Back 3

CH₃(CH₂)₅CH=CH(CH₂)₇COOH

16:1Δ9

Omega-7 fatty acid

104.5 ATP from degradation

Front 4

Oleic acid

Back 4

CH₃(CH₂)₇CH=CH(CH₂)₇COOH

18:1Δ9

Omega-9 fatty acid

118.5 ATP from degradation

Front 5

Linoleic acid

Back 5

CH₃(CH₂)₅CH=CH(CH₂)CH=CH(CH₂)₇COOH

18:2Δ9,12

Omega-6 fatty acid

Pro-inflammatory cytokines

116 ATP from degradation

Front 6

Linolenic acid

Back 6

CH₃CH₂CH=CH(CH₂)CH=CH(CH₂)CH=CH(CH₂)₇COOH

18:3Δ9,12,15

Omega-3 fatty acid

Anti-inflammatory cytokines

113.5 ATP from degradation

Front 7

Triacylglycerol

Back 7

-Anhydrous molecule

-Stores energy in adipose tissue

-Glycerol backbone with 3 fatty acids

Front 8

TAG synthase complex

Back 8

-Active in liver and adipose cells

-Formation of triacylglycerols from glycerol and activated fatty-acid components

Front 9

Glycerol-3-phosphate dehydrogenase

Back 9

TAG synthase complex step 1

Dihydroxyacetone phosphate + NADH --->

Glycerol-3-phosphate + NAD+

Front 10

Glycerol kinase

Back 10

TAG synthase complex step 1 (alternate)

Dietary glycerol + ATP --->

glycerol-3-phosphate + ADP

Front 11

Glycerophosphate acyltransferase

Back 11

TAG synthase complex step 2

Glycerol-3-phosphate + FA-SCoA -->

Lysophosphatidate (LPA) + HSCoA

Front 12

Lysophosphatidic acid acyltransferase

Back 12

TAG synthase complex step 3

LPA + FA-SCoA -->

Phosphatidate + HSCoA

Front 13

Phosphatidate phosphatase

Back 13

TAG synthase complex step 4

Phosphatidate + H2O -->

Diacylglycerol (DAG) + Pi

Front 14

Diacylglycerol acyltransferase

Back 14

TAG synthase complex step 5

DAG + FA-SCoA -->

Triacylglycerol + HSCoA

Front 15

VLDL

Back 15

Very Low Density Lipoprotein

-Constructed in liver tissue

-Carries TAGs and Cholesterol-esters

-Surrounded by phosphatidyl-choline and cholesterol monolayer

-Apo-C II complexed lipoprotein

-Deliver TAGs to adipose tissue

Front 16

CTP:PA transferase

Back 16

Phosphatidate activation for modification

Phosphatidate + CTP -->

CDP-Diacylglycerol + PPi

Front 17

Phosphatidyl inositol synthase

Back 17

PI synthesis

CDP-DAG + Inositol -->

Phosphatidyl inositol + CMP

Front 18

Phosphatidyl glycerol synthase

Back 18

PG synthesis step 1

CDP-DAG + Glycerol-3-P -->

Phosphatidyl glycerol-3-P + CMP

Front 19

Phosphatidyl glycerol phosphatase

Back 19

PG synthesis step 2

Phosphatidyl glycerol-3-P + H2O -->

Phosphatodyl glycerol + Pi

Front 20

Cardiolipin synthase

Back 20

CL synthesis

CDP-DAG + Phosphatidyl glycerol -->

Cardiolipin + CMP

Front 21

Choline kinase

Back 21

PC synthesis step 1

Choline + ATP -->

Phosphocholine + ADP

Front 22

CTP:Phosphocholine transferase

Back 22

PC synthesis step 2

Phosphocholine + CTP -->

CDP-choline + DAG + PPi

Front 23

CDP-choline:DAG transferase

Back 23

PC synthesis step 3

CDP-choline + DAG -->

Phosphatidylcholine + CMP

Front 24

Phosphatidylethanolamine N-methyl transferase

Back 24

Methylation of PE to PC

PE + 3 S-adenosyl methionine -->

PC + 3 S-adenosyl homocysteine

Front 25

Phosphatidylserine synthase I

Back 25

PS synthesis

PC/PE + serine -->

Phospatidylserine + Choline/ethanolamine

Front 26

Phosphatidylserine decarboxylase

Back 26

PE synthesis from PS

PS -->

PE + CO2

Front 27

Sphingolipids

Back 27

-Amphipathic membrane lipids

-Sphingosine backbone from palmitate and serine derivatives containing a trans bond and a hydroxyl group on C3

-Different head groups with different charges, polarity, etc.

Front 28

Ceramide

Back 28

-Sphingolipid with one fatty acid

Front 29

Sphingomyelin

Back 29

-Sphingolipid with phosphocholine on C1

-Major component in myelin sheath

Front 30

Cerebroside

Back 30

-Sphingolipids with glucose or galactose group of C1

-Polar head group

-Isolated from nerve sheaths

Front 31

Ganglioside

Back 31

-Sphingolipid with complex oligosaccharide group on C1

Front 32

Cholesterol

Back 32

-Synthesized in liver from acetyl-CoA, promoted by insulin

-Amphipathic due to polar OH group

-Component of cell membranes

-Synthesizes steroids and cortisol in adrenal tissue

Front 33

Thiolase (cytoplasmic)

Back 33

Cholesterol synthesis step 1

2 Acetyl-CoA <---> Acetoacetyl-CoA + HSCoA

Front 34

HMG-CoA synthase

Back 34

Cholesterol synthesis step 2

Acetoacetyl-CoA + Acetyl-CoA -->

B-hydroxy-B-methylglutary-CoA + HSCoA

Front 35

HMG-CoA reductase

Back 35

Cholesterol synthesis step 3

HMG-CoA + 2 NADPH + H+ -->

Mevalonate + HSCoA + 2 NADP+

Key regulatory enzyme

Upregulated by insulin

Downregulated by glucagon

Inhibited by cholesterol

Front 36

Acyl-CoA-Cholesterol acyl transferase

Back 36

Cholesterol ester biosynthesis

Cholesterol + Acyl-CoA -->

Cholesterol ester + HSCoA

Activated by cholesterol

Front 37

Lipoprotein lipase

Back 37

-Recognize surface proteins of VLDL/LDL and catalyze reaction:

TAG + 3 H2O --> 3 FA + glycerol

-Products cross over into tissues and resynthesized

Front 38

Acyl-CoA synthetase

Back 38

Fatty-acid activation

FA + CoA + ATP --> Acyl-CoA + AMP

Front 39

LDL

Back 39

Low Density Lipoprotein

-Carries cholesterol-esters

-Surrounded by phosphatidyl-choline and cholesterol monolayer

-Apo-B 100 complexed lipoprotein

-Deliver CEs to extrahepatic tissue

Front 40

Cholesterol esterase

Back 40

Uptake of cholesterol

CE + H2O --> Cholesterol + 1 FA

Front 41

Bile Salts

Back 41

-Synthesized in liver

-50% of new cholesterol converted to bile salts

-Stored in gall bladder, delivered to small intestine

-Isolate TAGs for digestion

-95% returned to liver from small intestine via receptors

Front 42

Oxidation of cholesterol by Cytochrome P450

Back 42

Bile salt synthesis

Front 43

Covalent attachment of glycine to cholic acid

Back 43

Bile salt synthesis

Front 44

Covalent attachment of taurine to cholic acid

Back 44

Bile salt synthesis

Front 45

Cholestyramine

Back 45

-Non digestible positively charged polymer

-Attracted to charged bile salts (taurocholic acid)

-Block re-absorption of bile salts

Front 46

HDL

Back 46

High Density Lipoprotein

-Synthesized in liver and intestinal cells

-Protein rich particle scavenges excess cholesterol in the bloodstream

-Contains LCAT

-Cholesterol converted to CEs and transported back to liver

Front 47

Lecithin-cholesterol acyl transferase

Back 47

Esterification of cholesterol

Cholesterol + lecithin --->

Cholesterol ester + Lysolecithin

Front 48

Plasmalogen

Back 48

-Found in myelin sheaths

-X = CH2-CH2-NH3+

Front 49

Prenyl group

Back 49

-Synthesized from squalene

-Bulky

Front 50

pancreatic TAG lipase

Back 50

Digestion of dietary fats

TAG + 2 H2O -->

Monoacylglyceride (A2 position) + 2 FA

**Colipase cofactor

Front 51

Orlistat

Back 51

Competitive inhibitor of TAG lipase

Front 52

Pancreatic A2 lipase

Back 52

Digestion of dietary fats

MAG + H2O --> glycerol + FA

Front 53

Chylomicrons

Back 53

-Less dense than VLDL/LDLs, but much larger

-Constructed in intestinal cells

-90% TAG composition, 4% CE composition

-Deliver TAGs to adipose, muscle and mammary tissue

-Return to liver for recylcling

Front 54

Perilipin

Back 54

Storage protein associated with phospholipid monolayer surrounding TAGs in adipose tissue

Front 55

Hormone Sensitive Lipase

Back 55

-HSL

-Break down stored TAGs in adipose tissue (when activated)

Front 56

Protein kinase A

Back 56

Mobilization of TAGs in adipose tissue

-Activated by cAMP via hormone signaling from glucagon/epinephrine

perilipin/HSL ---> phosphorylated perilipin/HSL

Front 57

Serum albumin

Back 57

-Bind free FAs in bloodstream for transport

~10 FAs per protein

Front 58

Carnitine acyl-transferase I

Back 58

Fatty acid degradation

Carnitine + Acyl-CoA --> Acyl-carnitine + HSCoA

-Located on outer surface of outer mitochondrial membrane

-Key regulatory step

-Inhibited by Malonyl-Coa

Front 59

Carnitine carrier protein

Back 59

-Located on inner mitochondrial membrane

-Antiport exchange

-Acyl-carnitine into mitchondrial matrix in exchange for carnitine(mit)

Front 60

Carnitine acyl-transferase II

Back 60

Fatty acid degradation

Acyl-carnitine + HSCoA --> Acyl-CoA + carnitine

Front 61

Acyl-CoA dehydrogenase

Back 61

β-oxidation of Fatty acids step 1

Acyl-CoA + FAD -->

trans Δ2 Enoyl-CoA + FADH2

Front 62

Enoyl-CoA hydratase

Back 62

β-oxidation of Fatty acids step 2

trans Δ2 Enoyl-CoA + H2O -->

L-3-hydroxylacyl-CoA

Front 63

Hydroxyacyl-CoA dehydrogenase

Back 63

β-oxidation of Fatty acids step 3

L-3-hydroxylacyl-CoA + NAD+ -->

3-ketoacyl-CoA + NADH + H+

Front 64

Thiolase (mitochondrial)

Back 64

β-oxidation of Fatty acids step 4

3-ketoacyl-CoA + HSCoA -->

Acyl-CoA + Acetyl-CoA

Front 65

Δ3,Δ2 Enoyl-Coa isomerase

Back 65

β-oxidation of Fatty acids (skip step 1)

cis Δ3 Enoyl-CoA --> trans Δ2 Enoyl-CoA

Front 66

2,4-dienoyl-CoA reductase

Back 66

β-oxidation of Fatty acids

trans Δ2, cis Δ4 Enoyl-CoA + NADPH + H+ -->

trans Δ2 Enoyl-CoA

Front 67

Propionyl-CoA carboxylase

Back 67

β-oxidation of Fatty acids

Propionyl-CoA + HCO3- + ATP -->

D-Methylmalonyl-CoA + ADP + Pi

*biotin cofactor

Front 68

Methylmalonyl-CoA epimerase

Back 68

β-oxidation of Fatty acids

D-Methylmalonyl-CoA --> L-Methylmalonyl-CoA

Front 69

Methylmalonyl-CoA mutase

Back 69

β-oxidation of Fatty acids

L-Methylmalonyl-CoA --> Succinyl-CoA

*B12 coenzyme

Front 70

Pepsin

Back 70

Digestive enzyme, active in the stomach at

pKa = 2

Front 71

Aminopeptidase

Back 71

Digestive enzyme active in the intestine, breaks down oligopeptides

Front 72

H+ symport

Back 72

Transporter for di and tripeptides from intestinal lumen into intestine cells

Front 73

Na+ symport

Back 73

Transporter for amino acids from intestinal lumen into intestine cells

Front 74

Alanine aminotransferase

Back 74

Front 75

Glutamate dehydrogenase

Back 75

Urea cycle step 1

Glutamate + H2O + NADP+ -->

α-ketoglutarate + NADPH + H+ + NH4+

Front 76

Carbamoyl-phosphate synthetase

Back 76

Urea cycle step 2

NH4+ + 2 ATP + HCO3- -->

Carbamoyl-phosphate + 2 ADP + Pi

Key regulatory enzyme

Activation strategy 1: Acyl-P

Channelling mechanism

Allosterically activated by N-acetyl-glutamate

Front 77

N-acetyl-glutamate synthase

Back 77

Urea cycle regulatory step

Acetyl-CoA + glutamate -->

N-acetyl-glutamate + CoA

Front 78

Ornithine transcarbamylase

Back 78

Urea cycle step 3

Carbamoyl-P + ornithine --> citrulline + Pi

Front 79

Ornithine/Citruline translocase

Back 79

Urea cycle step 4

Citrulline + H+ ---->

<---- Ornithine (1+ charge)

Across mitochondrial membrane

Front 80

Arginino succinate synthetase

Back 80

Urea cycle step 5

Citrulline + ATP + aspartate -->

Argininosuccinate + AMP + PPi

Activation strategy 2: AMP

Front 81

Argininosuccinase

Back 81

Urea cycle step 6

Argininisuccinate <---> arginine + fumarate

Front 82

Arginase

Back 82

Urea cycle step 7

Arginine + H2O --> ornithine + urea

Front 83

Urea

Back 83

Waste product excreted by mammals in the kidneys

Front 84

Glutamate synthetase

Back 84

Glutamine biosynthesis

Glutamate + ATP + NH4+ -->

Glutamine + ADP + Pi

Activation strategy 1: Acyl-P

Front 85

Glutamate kinase

Back 85

Proline biosynthesis step 1

Glutamate + ATP --> γ-glutamyl-phosphate + ADP

Activation strategy 1: Acyl-P

Front 86

γ-Glutamyl-phosphate dehydrogenase

Back 86

Proline biosynthesis step 2

γ-glutamyl-phosphate + NADPH + H+ -->

Glutamate semialdehyde + NADP+ + Pi

Front 87

5PC reductase

Back 87

Proline biosynthesis step 3

Glutamate semialdehyde + H2O <---> 5PC + NADPH + H+ --->

Proline + NADP+

Front 88

Asparagine synthetase

Back 88

Asparagine biosynthesis

Aspartate + ATP + Glutamine + H2O

-->

Asparagine + PPi + AMP + Glutamate

Activation strategy 2: AMP

Front 89

3-phosphoglycerate dehydrogenase

Back 89

Serine biosynthesis step 1

3-PGA + NAD+ --> 3-phosphohydroxy pyruvate + NADH + H+

Front 90

3-phosphoserine aminotransferase

Back 90

Serine biosynthesis step 2

3-phosphohydroxy pyruvate + glutamate -->

3-phosphoserine + α-ketoglutarate

PLP coenzyme

Front 91

3-phosphoserine phosphatase

Back 91

Serine biosynthesis step 3

3-phosphoserine + H2O --> serine + Pi

Front 92

Serine hydroxy methyl transferase

Back 92

Glycine biosynthesis

Serine + THF -->

Glycine + H2O + N5,N10 methylene THF

Front 93

PRPP synthetase

Back 93

Nucleic acid biosynthesis

Ribose-5-P <--> β-D Ribose-5-P + ATP -->

PRPP + AMP

Activation strategy 3: PPi

Front 94

Adenylosuccinate synthetase

Back 94

AMP biosynthesis step 1

Inosinate + aspartate + GTP -->

adenylosuccinate + GDP + Pi

Activation Strategy 1: Pi

Front 95

Adenylosuccinate lyase

Back 95

AMP biosynthesis step 2

Adenylosuccinate --> Adenylate (AMP) + fumarate

Front 96

IMP dehydrogenase

Back 96

GMP biosynthesis step 1

Inosinate + H2O + NAD+ -->

Xanthylate

Front 97

GMP synthetase

Back 97

GMP biosynthesis step 2

Xanthylate + Glutamine + H2O + ATP -->

Guanylate (GMP) + Glutamate + AMP + PPi

Activation Strategy 2: AMP activation