Final answer:
Phospholipids and fats are similar as both are partly hydrophobic, have glycerol, and can vary in their fatty acid content. However, phospholipids are amphipathic (having both hydrophobic and hydrophilic properties) while fats do not share this characteristic.
Step-by-step explanation:
Phospholipids and fats (triacylglyerols) are similar in many aspects but they differ in characteristics when it comes to being amphipathic. Phospholipids are amphipathic molecules meaning they contain both hydrophilic (water-attracting) and hydrophobic (water-repelling) parts. The hydrophilic part is the phosphate-containing group, and the hydrophobic part is the fatty acid chains. In contrast, fats are not amphipathic; they are predominantly hydrophobic.
Both phospholipids and fats contain a compound called glycerol and can vary in their fatty acid composition. However, only two of glycerol's three binding positions are linked to fatty acids in phospholipids, and the third is bound to a phosphate group. In fats, all three positions are occupied by fatty acids. Therefore, both phospholipids and fats share hydrophobic traits, contain glycerol and may vary in their fatty acid constitution, but only phospholipids are amphipathic, not fats.
Learn more about Phospholipids and Fats