Acyl-coa dehydrogenase

Definition

Acyl-CoA dehydrogenase is an enzyme that plays a crucial role in the beta-oxidation of fatty acids, facilitating the first step in the breakdown of long-chain fatty acids into acetyl-CoA units. This enzyme catalyzes the oxidative removal of hydrogen from acyl-CoA substrates, converting them into trans-2-enoyl-CoA, while simultaneously reducing FAD to FADH2, which is later used in the electron transport chain for energy production. The activity of this enzyme is essential for efficient energy metabolism and lipid degradation.

5 Must Know Facts For Your Next Test

1. Acyl-CoA dehydrogenase exists in several forms, including long-chain, medium-chain, and short-chain variants, each specific to different lengths of fatty acid substrates.
2. Deficiencies in acyl-CoA dehydrogenase can lead to metabolic disorders such as medium-chain acyl-CoA dehydrogenase deficiency (MCADD), resulting in the inability to properly metabolize certain fats.
3. The action of acyl-CoA dehydrogenase generates FADH2, which feeds into the electron transport chain, highlighting its role in linking fatty acid degradation to ATP production.
4. Acyl-CoA dehydrogenase operates within the mitochondria, which are the powerhouse of the cell where fatty acid oxidation primarily takes place.
5. Inhibition or dysfunction of acyl-CoA dehydrogenase can lead to increased levels of acylcarnitines in the blood, which are indicative of disrupted fatty acid metabolism.

Review Questions

• How does acyl-CoA dehydrogenase contribute to the process of beta-oxidation?
  • Acyl-CoA dehydrogenase initiates beta-oxidation by catalyzing the oxidative removal of hydrogen from acyl-CoA molecules, transforming them into trans-2-enoyl-CoA. This is a crucial first step in breaking down fatty acids into acetyl-CoA units. The FADH2 produced during this reaction is vital for energy production as it enters the electron transport chain, demonstrating how this enzyme connects lipid degradation with cellular respiration.
• What are some clinical implications associated with deficiencies in acyl-CoA dehydrogenase enzymes?
  • Deficiencies in various forms of acyl-CoA dehydrogenase can lead to serious metabolic disorders, notably medium-chain acyl-CoA dehydrogenase deficiency (MCADD). Individuals with this condition struggle to metabolize medium-chain fatty acids, leading to toxic accumulation and hypoglycemia during fasting or illness. Early diagnosis and management are essential to prevent severe complications such as metabolic crises or sudden infant death syndrome (SIDS).
• Evaluate how the function of acyl-CoA dehydrogenase integrates with broader metabolic pathways and its importance for energy homeostasis.
  • The function of acyl-CoA dehydrogenase is integral to energy homeostasis as it connects fatty acid metabolism to ATP production through beta-oxidation. By producing FADH2 and acetyl-CoA, this enzyme not only facilitates the conversion of stored lipids into usable energy but also links lipid metabolism with other pathways like the citric acid cycle. Disruptions in this enzyme's activity can affect overall energy balance in cells and lead to metabolic diseases, emphasizing its significance in maintaining metabolic health.

Related terms

Beta-oxidation: A metabolic process involving the breakdown of fatty acids into acetyl-CoA units, generating energy through the production of FADH2 and NADH.

Acetyl-CoA: A central metabolite formed from the breakdown of carbohydrates, fats, and proteins, serving as a key substrate for the citric acid cycle.

FADH2:

A reduced form of flavin adenine dinucleotide that acts as an electron carrier in the electron transport chain, contributing to ATP production.