Please select the FALSE statement regarding lipids. Short-chain fatty acids contain five or fewer carbon atoms and may reduce the risk of colon cancer. Butyrate is a long-chain fatty acid that is produced by gut bacteria when they degrade undigested plant material. Phospholipids resemble triglycerides but one fatty acid is replaced with a phosphate group. A wax is a long-chain fatty acid covalently bonded to a long-chain alcohol and is insoluble in water. Steroids differ in structure from lipids but are classified as such because they are insoluble in water.
The Correct Answer and Explanation is:
The FALSE statement regarding lipids is:
“Butyrate is a long-chain fatty acid that is produced by gut bacteria when they degrade undigested plant material.”
Explanation:
Butyrate, also known as butyric acid, is in fact a short-chain fatty acid (SCFA), not a long-chain fatty acid. It contains only four carbon atoms (C4:0), placing it well within the SCFA category, which includes fatty acids with fewer than six carbon atoms. SCFAs like acetate (C2), propionate (C3), and butyrate (C4) are primarily produced through the fermentation of dietary fibers by gut microbiota in the colon.
Butyrate plays several important roles in human health:
- It serves as the primary energy source for colonocytes (cells lining the colon).
- It exhibits anti-inflammatory and anticarcinogenic properties.
- It may help reduce the risk of colon cancer and contribute to gut health.
By contrast, long-chain fatty acids typically contain 12 or more carbon atoms. Examples include palmitic acid (C16:0) and stearic acid (C18:0). Thus, categorizing butyrate as a long-chain fatty acid is incorrect.
Clarification of Other Statements (All TRUE):
- Short-chain fatty acids contain five or fewer carbon atoms…
✅ Correct. These fatty acids, such as butyrate, may reduce colon cancer risk. - Phospholipids resemble triglycerides…
✅ Correct. In phospholipids, one fatty acid in a triglyceride is replaced with a phosphate group, giving them unique amphipathic properties important in cell membranes. - A wax is a long-chain fatty acid covalently bonded to a long-chain alcohol…
✅ Correct. This structure makes waxes hydrophobic and water-insoluble. - Steroids differ in structure from lipids but are classified as such because they are insoluble in water.
✅ Correct. Steroids have a fused ring structure but are considered lipids due to their hydrophobic nature.
Thus, the false statement is the one incorrectly identifying butyrate as a long-chain fatty acid.
