Energy economy of the cells

Glucose --- ready cashLipids --- savings account

Fatty acids (from triacylglycerols) catabolization Citric acid cycle ATP

Acetyl-CoA

synthesis

Lipids

Catabolism of Lipids

Phospholipiase D

in spider and snake venom

Lipid products of hydrolysis

Lyse red blood cells

Prevent clot formation

Hormone-dependenthydrolysis of triacylglyerols

The formation of an acetyl-CoA in cytosol(activation step requires two ATP)

Role of carnitine in the transfer of acyl groups to the mitochondrial matrix

Carnitine translocase

Carnitine acyltransferase

-oxidation of saturated fatty acids

One cycle:2 C shorten1 acetyl-CoA formed1 FADH2 formed1 NADH formed

Degradation of stearic acid (18 C) through -oxidation

The energy yield from the oxidation of fatty acids

CH3(CH2)16C-S-CoA + 8FAD + 8NAD+ + 8H2O + 8CoA-SH

9CH3-C-S-CoA + 8FADH2 + 8NADH + 8H+

O

O

9CH3-C-S-CoA + 9FAD + 27NAD + + 9GDP + 9Pi + 27 H2O 18CO2 + 9CoA-SH + 9FADH2 + 27NADH + 9GTP + 27H+

O

17FADH2 + 8.5O2 + 25.5ADP + 25.5Pi 17 FAD + 25.5 ATP + 17 H2O35NADH + 35H+ + 17.5 O2 + 87.5ADP + 87.5Pi 35NAD+ + 87.5ATP + 35H2O

CH3(CH2)16C-S-CoA + 26O2 + 122 ADP + 122Pi 18CO2 + 17H2O + 122ATP + CoA-SH

O

one 18C fatty acid 120 ATP one 6C glucose 32 ATP

CytosolMatrix in mitochondia Citric acid cycle Electron transport chain

The balance sheet for oxidation of one molecule of stearic acid

CH3(CH2)16C-S-CoA + 26O2 + 122 ADP + 122Pi 18CO2 + 17H2O + 122ATP + CoA-SH

O

Metabolic water

The oxidation of a fatty acid containing an odd number of carbon atoms

-oxidation of unsaturated fatty acids

The oxidation pathways for polyunsaturated fatty acids

The anabolism of fatty acids

● Oxaloacetate and acetyl-CoA can not cross through mitochondria membrane but citrate can.

fatty acid synthesis in cytosol

The formation of malonyl-CoA --- the first step in anabolism of fatty acids

Acetyl-CoA carboxylase

Three proteins making up acetyl-CoA carboxylase

The first cycle of palmitate synthesis

ACP: acyl carrier protein

Fatty acid synthase

ACP has a functional group that is structurally similar to coenzyme A

The second cycle of palmitate synthesis in E. coli

In E. coli,multienzyme system

In eukaryotes,multifunctional enzyme

16C saturated fatty acid (palmitate)

A comparison of fatty acid degradation and biosynthesis

Chain lengthening beyond 16C

Pathways for the biosynthesis of triacylglycerols

Pathways for the biosynthesis of phosphoacylglycerols (I)

In E. coli

Pathways for the biosynthesis of phosphoacylglycerols (II)

In mammals

The interconversion of PE and PS in mammals

The anabolism of cholesterol

C2 C6 C5

C30

C27

● Most of the cholesterol formed in the smooth ER of the liver in mammals

The biosynthesis of mevalonate 2 acetyl-CoA

●This step is inhibited by high levels of cholesterol and is the major control point of cholesterol synthesis

●A target for drugs to lower cholesterol levels in the body

●lovastatin an inhibitor of HMG-CoA reductase

The synthesis of Squalene

The synthesis of bile acids from cholesterol

The synthesis of steroid hormones from cholesterol

The role of cholesterol in heart disease

● Deposition of cholesterol plaques atherosclerosis

● Cholesterol is transported by lipoproteins in bloodstream

● Lipoprotein aggregates are classified by their densities

LDL (low-density lipoproteins) particles

Lipids: cholesterol triacylglycerols cholerserol esters phospholipids

The fate of cholesterol in the cell

Proteins in LDL amino acidsCholesterol ester fatty acids + cholesterol

ACAT (acyl-CoA cholesterol acyltransferase)

HMG-CoA reductase

Synthesis of LDL receptors

lysosomes