1.
What is the primary precursor for fatty acid synthesis?
Correct Answer
B. Acetyl-CoA
Explanation
Acetyl-CoA is a crucial precursor in fatty acid synthesis, providing the foundational building blocks for the intricate process. As a two-carbon molecule, Acetyl-CoA is central to the biosynthesis of fatty acids, serving as the starting point for the elongation of these essential cellular components.
2.
Which enzyme is responsible for the committed step in fatty acid synthesis?
Correct Answer
A. Acetyl-CoA Carboxylase
Explanation
Acetyl-CoA Carboxylase plays a pivotal role in fatty acid synthesis by catalyzing the committed step. This enzyme transforms Acetyl-CoA into malonyl-CoA, a key intermediate. Malonyl-CoA, in turn, serves as the foundation for the formation of the growing fatty acid chain, initiating the complex cascade of molecular events inherent in lipid biosynthesis.
3.
In fatty acid synthesis, what is the role of malonyl-CoA?
Correct Answer
B. Fatty acid initiation
Explanation
Malonyl-CoA is instrumental in the initiation phase of fatty acid synthesis. Serving as a substrate, Malonyl-CoA contributes the initial two-carbon unit necessary for the elongation of the fatty acid chain. This early stage sets the foundation for the subsequent intricate processes involved in lipid production.
4.
What is the end product of the fatty acid synthesis pathway?
Correct Answer
A. Palmitate
Explanation
Palmitate, a 16-carbon saturated fatty acid, emerges as the end product of the fatty acid synthesis pathway. This compound holds significance as a prevalent and vital component of cellular structures, embodying the culmination of the intricate biochemical machinery orchestrating lipid biosynthesis.
5.
Which co-factor is essential for the activity of fatty acid synthase?
Correct Answer
B. NADpH
Explanation
Fatty acid synthase relies on NADPH as a cofactor, playing a crucial role in the reduction steps during fatty acid chain elongation. This coenzyme provides the necessary reducing equivalents for the synthesis of saturated fatty acids, contributing to the intricate dance of biochemical reactions within the cellular milieu.
6.
What inhibits acetyl-CoA carboxylase, a key enzyme in fatty acid synthesis?
Correct Answer
C. Palmitate
Explanation
Palmitate inhibits acetyl-CoA carboxylase (ACC), a key enzyme in fatty acid synthesis. Acetyl-CoA carboxylase catalyzes the conversion of acetyl-CoA to malonyl-CoA, the first step in the synthesis of fatty acids. Palmitate, a long-chain saturated fatty acid, acts as a feedback inhibitor for this enzyme. When levels of palmitate are high, it signals that the cell has sufficient fatty acids, leading to the inhibition of ACC to prevent excess fatty acid synthesis. This regulatory mechanism helps maintain balanced fatty acid levels within the cell.
7.
During fatty acid synthesis, where does the process predominantly occur in eukaryotic cells?
Correct Answer
C. Cytosol
Explanation
Fatty acid synthesis predominantly unfolds in the cytosol of eukaryotic cells. This cellular compartment houses the enzymatic machinery, including fatty acid synthase, essential for the intricate synthesis of fatty acids. The cytosolic environment provides a tailored setting for these biosynthetic processes.
8.
What is the purpose of the glycerol-3-phosphate shuttle in triglyceride synthesis?
Correct Answer
A. Glycerol transport
Explanation
The glycerol-3-phosphate shuttle serves a critical role in triglyceride synthesis by facilitating the transport of glycerol, a fundamental component of these complex molecules. This shuttle ensures the efficient incorporation of glycerol into the synthesis of triglycerides, contributing to cellular energy storage.
9.
Which hormone activates lipogenesis and fatty acid synthesis?
Correct Answer
A. Insulin
Explanation
Insulin, a pivotal hormone, activates lipogenesis and fatty acid synthesis by orchestrating glucose uptake and enhancing the activity of key enzymes. This hormonal regulation underscores the integration of metabolic pathways and hormonal signaling in cellular lipid homeostasis.
10.
In fatty acid synthesis, what is the function of the thioesterase domain of fatty acid synthase?
Correct Answer
B. Terminates fatty acid synthesis
Explanation
The thioesterase domain of fatty acid synthase is integral to the termination of fatty acid synthesis. This domain releases the completed fatty acid chain from the enzyme complex, marking the conclusion of the intricate molecular process of lipid biosynthesis. The controlled termination ensures the precise production of fatty acids within the cellular context.