Which type of nutrient uptake involves the engulfment of small dissolved molecules into vesicles?

• A. Receptor-mediated endocytosis
• B. Exocytosis
• C. Phagocytosis
• D. Pinocytosis

Answer: (D)

Verified step by step guidance

1. Understand the different types of endocytosis: Endocytosis is a cellular process in which substances are brought into the cell. There are different types of endocytosis, including phagocytosis, pinocytosis, and receptor-mediated endocytosis.
2. Define pinocytosis: Pinocytosis is a type of endocytosis where the cell engulfs small dissolved molecules and fluids into small vesicles. It is often referred to as 'cell drinking.'
3. Differentiate between phagocytosis and pinocytosis: Phagocytosis involves the engulfment of large particles or cells, often referred to as 'cell eating,' whereas pinocytosis involves the uptake of liquids and small molecules.
4. Consider receptor-mediated endocytosis: This is a selective form of endocytosis where specific molecules are ingested into the cell after binding to receptors on the cell surface.
5. Identify the correct process: Given the options and definitions, pinocytosis is the process that involves the engulfment of small dissolved molecules into vesicles, distinguishing it from the other types of nutrient uptake.