Fatty acid synthase

Definition

Fatty acid synthase is a multi-enzyme complex responsible for the synthesis of fatty acids, particularly palmitate, from acetyl-CoA and malonyl-CoA. This enzyme plays a crucial role in lipid metabolism and is involved in various cellular functions, including energy storage and membrane formation. By catalyzing the stepwise addition of two-carbon units to a growing fatty acid chain, it helps maintain cellular lipid homeostasis and contributes to the production of signaling molecules.

5 Must Know Facts For Your Next Test

1. Fatty acid synthase operates as a dimer, meaning it consists of two identical subunits that work together to synthesize fatty acids efficiently.
2. The primary product of fatty acid synthase activity is palmitate, a 16-carbon saturated fatty acid that can be further elongated or desaturated into various other fatty acids.
3. Fatty acid synthase activity is regulated by nutritional status, with increased activity observed during high-carbohydrate diets when energy storage is prioritized.
4. In addition to its role in fatty acid synthesis, fatty acid synthase also plays a part in cellular signaling pathways related to growth and metabolism.
5. Dysregulation of fatty acid synthase has been linked to metabolic disorders, such as obesity and type 2 diabetes, highlighting its importance in maintaining metabolic health.

Review Questions

• How does fatty acid synthase contribute to cellular lipid homeostasis?
  • Fatty acid synthase contributes to cellular lipid homeostasis by synthesizing fatty acids, particularly palmitate, which are essential for energy storage and membrane formation. By regulating the balance of fatty acid synthesis and degradation, it ensures that cells maintain an appropriate level of lipids required for various cellular functions. This balance is crucial for optimal cell health and metabolic efficiency.
• Discuss the regulatory mechanisms that control the activity of fatty acid synthase in response to different nutritional states.
  • Fatty acid synthase activity is primarily regulated by the availability of substrates like acetyl-CoA and malonyl-CoA, as well as hormonal signals from insulin and glucagon. During high-carbohydrate diets, insulin levels rise, promoting the activation of fatty acid synthase to facilitate energy storage through lipid synthesis. Conversely, during fasting or low-carbohydrate intake, glucagon levels increase, leading to decreased fatty acid synthesis and enhanced fat mobilization for energy use.
• Evaluate the implications of fatty acid synthase dysregulation on metabolic diseases such as obesity and type 2 diabetes.
  • Dysregulation of fatty acid synthase has significant implications for metabolic diseases like obesity and type 2 diabetes. When fatty acid synthase is overactive, excessive lipid accumulation occurs in tissues, leading to insulin resistance and promoting inflammation. This imbalance disrupts normal metabolic processes, resulting in impaired glucose homeostasis. Therefore, targeting fatty acid synthase could provide therapeutic strategies for managing these metabolic disorders.

Related terms

Acetyl-CoA: A key molecule in metabolism that serves as a building block for the synthesis of fatty acids and is also involved in the Krebs cycle.

Malonyl-CoA: An intermediate in fatty acid synthesis, derived from acetyl-CoA, that provides the two-carbon units needed for chain elongation.

Lipid metabolism: The process by which lipids are synthesized and degraded in the body, playing a vital role in energy production, cell signaling, and maintaining membrane integrity.