Which reaction is catalysed by acetyl-CoA carboxylase?
Acetyl-CoA carboxylase (ACC) catalyses the formation of malonyl-CoA, an essential substrate for fatty acid synthesis in lipogenic tissues and a key regulatory molecule in muscle, brain and other tissues.
What is the function of acetyl-CoA carboxylase in de novo synthesis?
De novo fatty-acid synthesis is regulated by two important enzymes, namely acetyl-CoA carboxylase and fatty acid synthase. The enzyme acetyl CoA carboxylase is responsible for introducing a carboxyl group to acetyl CoA, rendering malonyl-CoA.
How do you activate acetyl-CoA carboxylase?
ACC is inactive when phosphorylated by the enzyme AMP-activated protein kinase (inhibited by ATP and activated by AMP), and acetyl-CoA carboxylase is activated by dephosphorylation via the enzyme protein phosphatase 2A (PP2A).
Which compound or hormone is a regulator of acetyl-CoA carboxylase chegg?
Citrate and Palmitoyl-CoA and regulate acetyl-CoA carboxylase.
How is acetyl-CoA carboxylase inhibited?
AMP-Activated Protein Kinase 44-4, when AMPK is activated (e.g., during exercise or in some tissues by caloric deprivation), it phosphorylates and inhibits acetyl CoA carboxylase (ACC), the enzyme that catalyzes the synthesis of malonyl CoA.
Which cofactor is involved in the carboxylation of acetyl-CoA?
EC no. CAS no. Acetyl-CoA carboxylase (ACC) is a biotin-dependent enzyme that catalyzes the irreversible carboxylation of acetyl-CoA to produce malonyl-CoA through its two catalytic activities, biotin carboxylase (BC) and carboxyltransferase (CT).
Which of the following events inactivates acetyl-CoA carboxylase?
Glucagon rapidly inactivates acetyl-coA carboxylase with an accompanying &fold increase in the phosphorylation of the enzyme and 3-fold increase in the protomer-polymer ratio of enzyme protein.
What is the function of nucleotide includes in de novo purine biosynthesis?
The products of de novo purine biosynthesis are the nucleoside monophosphates AMP and GMP. These nucleotides are converted by successive phosphorylation reactions into their metabolically prominent triphosphate forms, ATP and GTP.
What is the allosteric regulator of acetyl-CoA carboxylase?
The activity of ACC-1 is acutely controlled by allosteric modulators and by the phosphorylation of four or more serine residues. Among the allosteric effectors of ACC-1, citrate and other carboxylic acids activate the enzyme by promoting polymerization [6,16] (Table 1).
Does acetyl-CoA activate acetyl-CoA carboxylase?
Abstract. Acetyl-CoA carboxylase [acetyl-CoA:carbon-dioxide ligase (ADP-forming), EC 6.4. 1.2] is activated by physiological concentrations of CoA.
Why is acetyl-CoA carboxylase considered the key regulatory enzyme for citrate?
Acetyl-CoA carboxylase is considered the key regulatory enzyme in the conversion of citrate to long-chain fatty acids because (i) the concentrations of its substrates and products are far from thermodynamic equilibrium; (ii) the maximum velocity of the enzyme, as measured in cell extracts under optimal conditions,…
What is the role of ATP in acetyl-CoA carboxylase?
Acetyl-CoA carboxylase catalyzes the carboxylation of acetyl-CoA to malonyl-CoA. Hydrolysis of ATP provides the energy to drive this essentially irreversible reaction.
How does acetyl-CoA catalyze fatty acid synthesis?
Acetyl-CoA carboxylase catalyzes the first committed step of fatty acid synthesis. The overall reaction is composed of two distinct half reactions; the ATP-dependent carboxylation of biotin with bicarbonate to form carboxybiotin followed by transfer of the carboxyl group from carboxybiotin to acetyl-CoA to form malonyl-CoA (Fig. 4).
How does transcarboxylase catalyze malonyl CoA?
Second, the transcarboxylase component, a heterodimer composed of the accA and accD gene products, transfers the CO 2 moiety from biotin carboxyl carrier protein to acetyl-CoA to form malonyl-CoA. The two acetyl-CoA carboxylase half reactions are catalyzed by two different protein subcomplexes.