Which of the following statements is false?

• A. A hydrocarbon chain is just a linear molecule composed of only hydrogen and carbon atoms.
• B. Fatty acids are hydrocarbon chains with a carboxyl group at one end.
• C. Triglycerides consist of a 3-carbon glycerol backbone & 3 fatty acids.
• D. Triglycerides always have 3 identical fatty acids in terms of their length and number of double bonds.

Answer: (D)

Verified step by step guidance

1. Step 1: Begin by understanding the structure of hydrocarbons. Hydrocarbons are molecules composed solely of hydrogen and carbon atoms, typically forming linear or branched chains. This statement is true and foundational to understanding fatty acids and triglycerides.
2. Step 2: Examine the structure of fatty acids. Fatty acids are hydrocarbon chains with a carboxyl group (-COOH) at one end. This functional group is essential for their role in forming triglycerides and other lipids. This statement is also true.
3. Step 3: Analyze the composition of triglycerides. Triglycerides consist of a glycerol backbone (a 3-carbon molecule) attached to three fatty acids via ester bonds. This statement is accurate and describes the basic structure of triglycerides.
4. Step 4: Evaluate the statement about triglycerides always having three identical fatty acids. This is false because triglycerides can have three different fatty acids, varying in chain length and the number of double bonds (saturation level). This variability contributes to the diversity of triglycerides in biological systems.
5. Step 5: Conclude that the false statement is: 'Triglycerides always have 3 identical fatty acids in terms of their length and number of double bonds.' This is incorrect because triglycerides can contain a mix of fatty acids with different properties.