2.4.2 Metabolism III Flashcards
What are three of the essential fatty acids?
linoleic, linolenic, arachidonic acids
In what two ways does glucose contribute to fatty acid synthesis?
Providing carbons
Feeding the pentose phosphate pathway, which generates NADPH
What is the significance of ketogenesis?
What does reaction does insulin activate?
Malonyl-CoA -> Palmitate
Activation of Acetyl CoA carboxylase - leading to the formation of malonyl CoA which will inhibit FA breakdown
Ultimately, reducing the formation of ketone bodies
What is the enzyme deficiency of farber’s dz? accumulating lipid?
Ceramidase; Acyl-Sphingosine Ceramide
What is the enzyme deficiency in Gaucher’s dz? Accumulating lipid?
Beta-glucocerebrocidase; Glucosyl ceramide
What is multiple sclerosis? What is lost?
A demyelinating dz; phospholipids (particularly ethanolamine plasmalogen) and sphingolipids of white matter
What are the clinical symptoms of niemann-pick dz?
What are the clinical symptoms of the three types of gaucher’s dz?
What is the enzyme dificiency in Fabry’s Dz? Accumulating Lipid?
alpha-galactosidase; globotricylceramide
Under circumstances where significant fatty acid breakdown occurs, what organ will release ketones which can be used by other organs?
Liver
Describe the break down of fatty acids into a substrate that will feed into the TCA cycle
What is often bound to the individual enzymes of the fatty acid synthase system?
Acyl carrier protein (ACP), which contains pantothenic acid
How is ceramide synthesized?
Other than citrate, what two substances can regulate Acetyl-CoA Carboxylase?
Glucagon and insulin
Where must acetyl CoA be sent in order for it to undergo fatty acid biosynthesis?
It must be shipped from the matrix of the mitochondrion to the cytosol via a transport system.
What is a key steps in the biosynthesis of fatty acids?
Acetyl CoA -> Malonyl CoA
Enzyme: Acetyl CoA Carboxylase (ACC)
Reaction requires: biotin
What is the most important enzyme in the regulation of lipogenesis? What activates this enzyme?
Acetyl-CoA Carboxylase; Citrate
What this be?
Sphingomyelin
What are two enzymes which regulate fatty acid oxidation?
Acetyl CoA Carboxylase
and
Carnitine Palmitoyl-Transferase
How are free fatty acids carried?
BSA complexes
What does Acyl-CoA inhibit?
The mitochondrial tricarboxylate transporter
What feeds into the TCA cycle? What is produced?
Acetyl-CoA; ATP
What are the clinical symptoms of Farber’s dz?
What enzyme converts malate to pyruvate while producing NADPH?
The malic enzyme
Describe the process of odd chain fatty acid oxidation.
What are the clinical symptoms of Fabry’s dz?
What are the clinical symptoms of tay sachs?
What is ketoacidosis?
What the two substances that can be made from acetoacetate?
Acetone and D(-)-3-hydroxybutyrate
Where are additional ezymes required in fatty acid synthesis found, which elongate and desaturate fatty acids?
The ER
What are the four components of Coenzyme A?
The business end is circumscribed in red
Remember: pantothetic acid
What is the enzyme deficiency in tay sachs dz? accumulating lipid?
Hexosaminidase A; GM2 ganglioside
What is required for most of the reductive steps involved in fatty acid biosynthesis?
NADPH
What are the four consequences of sphingolipidoses (lipid storage dz)?
Phosphatidic acid acts as a precursor to what?
Phospholipids and triglycerides
How are ketone bodies broken down in order to feed into the TCA?
What transporters are involved in transporting fatty acids into the mitochondrion?
Describe the intermediates which go from cytosol -> matrix of mitochondria? Matrix of mitochondria -> cytosol?
What is the enzyme deficiency in Niemann-Pick Dz? Accumulating lipid?
Sphingomyelinase; Sphingomyelin
