• The diagram on the left is titled ‘Cell With Normal LDL Receptors’. The diagram explains the process of breakdown of LDL in liver cells with normal LDL receptors. LDL receptors are indicated in green color. The sequence is indicated using arrow marks.
  1. LDL binds to receptor site. The caption reads ‘LDL from the blood binds to receptors on the cell membrane’.
  2. LDL is absorbed into the cell with the help of vesicles. The caption reads ‘LDL is taken into the cell’.
  3. The vesicle is broken down and the LDL receptors are recycled. The caption reads ‘The vesicle is broken LDL is broken down, and down, and the receptors are recycled’.
  4. LDL is broken down and components are stored. The caption reads ‘LDL is broken down, and its components are stored or used to make more cholesterol and bile’.
• The diagram on the right is titled ‘Cell With Defective LDL Receptors’.

The diagram explains the process that occurs in the presence of defective receptors. The defective receptors are indicated in red color.

1. LDL binds to receptors but is not absorbed into the cell. So, it builds up in the blood. The caption reads ‘LDL binds to receptors but cannot be taken into the cell. LDL builds up in the blood’.
2. Cells produce LDL and release it into blood. This is indicated by an arrow mark. The caption reads ‘Because the cell does not receive LDL from the blood, it makes LDL and releases even more of it into the blood’.