β-oxidation of fatty acids Flashcards
True or False, The only dietary nutrient in excess that can be converted to fatty acids are Carbohydrates.
False
Where does fatty acid synthesis take place
Liver, lactating mammary glands, and to a lesser extent adipose tissue
How is the mitochondrial Acetyl CoA produced, in the de novo fatty acid synthesis, produced
oxidation of pyruvate
catabolism of fatty acids, ketone bodies, certain amino acids
What is the first step in the de novo fatty acid synthesis
transfer of acetate units from mitochondrial acetyl CoA to the cytosol
How does acetyl get into the mitochondrial cytosol
Translocation of citrate produced by the condensation of oxaloacetate (OAA) and acetyl CoA, where acetyl is attached to the citrate
Where is the energy for the carbon-to-carbon condensations in fatty acid synthesis supplied from
Carboxylation and then decarboxylation of acetyl groups in the cytosol
In the presence of which hormones are Acetyl CoA Carboxylase inactivated through its phosphorylation
glucagon, epinephrine
In the presence of which hormones are Acetyl CoA activated by dephosphorylation
insulin
What is the major pathway for the catabolism of fatty acids
mitochondrial pathway called β-oxidation
What are the main products of β-oxidation
Acetyl CoA, NADH, FADH2
What is the name of the enzyme that converts long fatty acid chains into its CoA derivative (Fatty Acyl CoA)
long-chain fatty acyl CoA synthetase (thiokinase)
What is the name of the specialized carrier that transports the long-chain acyl group from the cytosol into the mitochondrial matrix
Carnitine
What is the name of the rate-limiting transport pro- cess
carnitine shuttle
Where is the long-chain fatty acyl CoA synthetase located
outer mitochondrial membrane
The conversion of Fatty acid chains and CoA to Fatty Acyl CoA due to energy given off from the conversion ATP to AMP is considered what type of reaction?
Coupled Reaction
What enzyme is used in the transfer of the Acyl group from Fatty Acyl CoA to Carnitine
Carnitine Palmitoyltransferase 1
Carnitine Acyl Transferase 1
What products are produced in the transfer of the Acyl group from Fatty Acyl CoA to Carnitine using Carnitine Acyl Transferase 1
CoA + Fatty Acyl Carnitine
What is transported into the mito- chondrial matrix in exchange for free carnitine by carnitine–acylcarnitine translocase.
Acylcarnitine
What enzyme is used in the inner mitochondrial membrane that catalyzes the transfer of the acyl group from Fatty Acyl carnitine to CoA in the mitochondrial matrix, thus regenerating the free carnitine
Carnitine palmitoyltrans- ferase II (CPT-II, or CAT-II)
Carnitine Acyl Transferase 2
Carnitine is found mainly in what type of products
Meat
What type of muscle contains majority of the body’s carnitine
Skeletal
Carnitine can be synthesised from the amino acids lysine and methionine by the enzymatic pathway found in which two organs
Kidney and Liver
Two ways in which Carnitine is formed in the body
Uptake of carnitine provided by endogenous synthesis or the diet
What are the two stages in β-oxidation of fatty acids.
1st: Removal of successive 2 Carbon units
2nd: Acetyl CoA oxidised to CO2 + H20
What type of reaction first starts the β- oxidation process in the matrix of the mitochondria
Dehydrogenation
What compound first starts the β- oxidation process in the matrix of the mitochondria
β-Carbon (3), α-Carbon (2)- Fatty Acyl CoA
Which enzyme facilitates the production of Enoyl CoA (2 trans), from Fatty Acyl CoA
Acyl CoA Dehydrogenases
What oxidising agent facilitates the production of Enoyl CoA (2 trans), from Fatty Acyl CoA
Fad+ to FADH2
What reaction is involved in the second step of the β- oxidation process
Hydration
What compound starts the 2nd step in the β- oxidation process
Enoyl CoA (2 trans)
What is the end product when H20 is added to Enoyl CoA (2 trans)
3-Hydroxyacyl CoA
What enzyme facilitates the hydration reaction in the second step
Enoyl CoA hydratase
What enzyme facilitates the production of 3-Ketoacyl CoA from 3-hydroxyacyl CoA
3-Hydroxyacyl CoA dehydrogenase
What oxidising agent facilitates the production of 3-Ketoacyl CoA from 3-hydroxyacyl CoA
Nad+
What type of reaction is the 3rd step in β- oxidation process
Dehydrogenation
What compound starts the 4th step in the β- oxidation process
3-Ketoacyl CoA
What enzyme is used in the 4th step in the β- oxidation process
β-Ketoacyl-CoA thiolase
What compound is involved in the synthesis of fatty acyl CoA and Acetyl CoA in the final step of the β-oxidation of fatty acyl CoA
CoA
What drug interrupt the active transport metabolic pathway
Amytal
At what level is CO2 released
Citric Acid Cycle
At what level is H2O released
Electron transfer chain
Differences between fatty acid synthesis and β-oxidation
Fatty acid synthesis occurs in the cytosol while β-oxidation occurs in mitochondria
Fatty acid synthase is the only enzyme involved in fatty acid synthesis while in β-oxidation many enzymes are involved
NAD is the oxidising agent in β-oxidation while NADP is the oxidising agent in fatty acid synthesis
The synthesis of what compound has similar pathways as β-oxidation of fatty acyl CoA
Cholesterol synthesis
What is one of the main compound involved in the electron transport chain
Ubiquitine
