What is smaller than a cell?

A structure or entity that is smaller than a cell includes the following:

1. Viruses: These are small infectious agents that can only replicate inside a host cell. They are smaller than cells and can be as small as 20 nanometers in size. Examples include HIV, Zika, and influenza.

2. Proteins: Proteins are biological macromolecules that perform various functions in the body. They are smaller than cells and can range in size from a few nanometers to hundreds of nanometers. Examples include insulin, collagen, and hemoglobin.

3. Lipids: Lipids are a class of molecules that include fats, oils, and waxes. They are smaller than cells and can be as small as a few nanometers. Lipids play a vital role in energy storage, cell membranes, and signaling.

4. Enzymes: Enzymes are proteins that catalyze chemical reactions in the body. They are smaller than cells and can range in size from a few nanometers to hundreds of nanometers. Examples include amylase, lactase, and pepsin.

5. DNA and RNA: DNA and RNA are nucleic acids that contain the genetic information of an organism. They are smaller than cells and can range in size from a few nanometers to tens of nanometers. DNA and RNA play a vital role in protein synthesis, cell division, and inheritance.