Two fatty acid monomers are joined by

Options

A. Ester bond
B. Peptide bond
C. Phospho diester bond
D. Hydrogen bond

Answer

To answer the question "Two fatty acid monomers are joined by," we can follow these steps:

### Step-by-Step Solution:

1. **Understanding Fatty Acids**: Fatty acids are long hydrocarbon chains with a carboxyl group (-COOH) at one end. They can be saturated or unsaturated.

2. **Formation of Fats**: In biological systems, fatty acids can combine with glycerol to form fats (triglycerides). This process involves the bonding of three fatty acids to a glycerol molecule.

3. **Type of Bond**: The bond that forms between the fatty acid and the glycerol is known as an ester bond. This occurs when the hydroxyl group (-OH) of the glycerol reacts with the carboxyl group (-COOH) of the fatty acid, resulting in the release of a water molecule (a dehydration synthesis reaction).

4. **Joining Two Fatty Acids**: When considering the joining of two fatty acid monomers, the same type of bond, the ester bond, is formed. This bond is crucial in the structure of triglycerides, which consist of three fatty acids linked to a glycerol backbone.

5. **Conclusion**: Therefore, the answer to the question is that two fatty acid monomers are joined by an ester bond.

### Final Answer:
Two fatty acid monomers are joined by an **ester bond**.

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