Question

called a phosphate group, the phosphate group is referred to as the head, and the fatty acid chains are the tails. the model shows the chemical structure of a phospholipid. select the true statements. unlike triglycerides, phospholipids have nitrogen and phosphorus atoms. fatty acids in a phospholipid are called tails. a phospholipid is made when one glycerol molecule combines with three fatty acids. phospholipids are used to build cell membranes.

Explanation:

1. For "Unlike triglycerides, phospholipids have nitrogen and phosphorus atoms": Triglycerides are composed of glycerol and three fatty acids (elements C, H, O). Phospholipids have a phosphate group (containing P) and often a nitrogen - containing group (e.g., choline), so they have N and P unlike triglycerides.
2. For "Fatty acids in a phospholipid are called tails": From the diagram and biological knowledge, the fatty acid parts of the phospholipid are referred to as the "tails" (while the phosphate - containing part is the "head").
3. For "Phospholipids are used to build cell membranes": In cell biology, the cell membrane is a phospholipid bilayer, so phospholipids are a major component of cell membranes.
4. For the incorrect statement "A phospholipid is made when one glycerol molecule combines with three fatty acids": Phospholipids have two fatty acid chains (tails) attached to glycerol, and a phosphate - containing group (head), whereas triglycerides have three fatty acid chains attached to glycerol.

Answer:

The true statements are:

• Unlike triglycerides, phospholipids have nitrogen and phosphorus atoms.
• Fatty acids in a phospholipid are called tails.
• Phospholipids are used to build cell membranes.

(Note: The statement "A phospholipid is made when one glycerol molecule combines with three fatty acids" is incorrect. Phospholipids have two fatty acid tails (not three) and a phosphate - containing head group, while triglycerides have three fatty acid tails.)