Question

What is the precursor molecule for fatty acid synthesis, where are the building blocks transported from, where are the synthesized fatty acids transported to, and which organs primarily synthesize fat?

A) Precursor Molecule: Acetyl-CoA; Transported from: Citric acid cycle intermediates; Transported to: Cellular membranes for energy storage; Organs: Liver and adipose tissue.

B) Precursor Molecule: Pyruvate; Transported from: Glycolysis; Transported to: Mitochondria for oxidation; Organs: Kidneys and heart.

C) Precursor Molecule: Glucose; Transported from: Glycogen stores; Transported to: Muscle cells for immediate energy use; Organs: Skeletal muscles and brain.

D) Precursor Molecule: Glycerol-3-phosphate; Transported from: Diet; Transported to: Muscle cells for energy production; Organs: Stomach and intestines.

Answer 1

The precursor molecule for fatty acid synthesis is acetyl-CoA, transported from the citric acid cycle intermediates in the mitochondria and synthesized primarily by the liver and adipose tissue. The synthesized fatty acids are stored in cellular membranes for energy storage. Correct option is A.

Step-by-step explanation:

The process of synthesizing fatty acids, known as lipogenesis, involves several precursors and transport mechanisms. The precursor molecule for fatty acid synthesis is acetyl-CoA. Acetyl-CoA is transported from the citric acid cycle intermediates, specifically from the mitochondria when it builds up. The transport of acetyl-CoA out of the mitochondria to the cytoplasm can be facilitated by citrate or acetylcarnitine. Once in the cytoplasm, lipogenesis occurs, and the synthesized fatty acids are then typically transported to be stored in cellular membranes as an energy reserve or converted into complex lipids. The primary organs responsible for the synthesis of fat are the liver and adipose tissue. Hence, the correct option from the given choices would be A).