Question 28

Molecules with hydrophilic heads and hydrophobic tails form membranes in a cell.

These molecules primarily function to create cell membranes, which are crucial for maintaining the structure and integrity of cells. The arrangement of hydrophilic heads facing outwards and hydrophobic tails facing inwards allows for the formation of a lipid bilayer that serves as a barrier to separate the internal environment of the cell from the external surroundings.

A) Catalyzes chemical reactions

This option is incorrect as molecules that catalyze chemical reactions are typically enzymes, which are proteins that facilitate biochemical processes. The amphipathic molecules described do not catalyze reactions; rather, they organize themselves to form structural components of the cell.

B) Stores energy

While some biological molecules, such as fats and carbohydrates, can store energy, the molecules in question are not primarily known for this function. Instead, their role is structural, contributing to the formation of membranes rather than energy storage.

C) Forms membranes

This option is correct because the described molecules, which possess hydrophilic heads and hydrophobic tails, arrange themselves in aqueous environments to create lipid bilayers. These bilayers are essential components of cellular membranes, providing a barrier that regulates the movement of substances in and out of the cell.

D) Stores genetic information

This option is incorrect as the storage of genetic information is primarily the role of nucleic acids, such as DNA and RNA. The molecules in question do not function in genetic storage but instead contribute to the physical structure of cell membranes.

Conclusion

In summary, the correct answer is that these molecules form membranes, a fundamental role in cellular architecture and function. Options A, B, and D fail to capture the primary characteristic of these molecules, which is their structural significance in creating barriers that facilitate cellular organization and homeostasis.