What term describes a pre-cellular entity with a few molecules inside?

The term that describes a pre-cellular entity with a few molecules inside is "protocell." Protocells are considered to be simple, membrane-bound structures that resemble the early forms of life. They are hypothesized to have been the first step toward the development of cellular life, containing essential components like nucleic acids and proteins, albeit in a rudimentary form. This term encapsulates the idea of an early precursor to living cells, highlighting the importance of membranes in forming the basic structure necessary for life’s emergence. The concept of protocells is significant in understanding the transition from non-living chemistry to living biological systems, as they offer insights into how simple molecular systems could give rise to complex life forms through natural processes.

The other terms listed refer to different biological concepts: "protoplast" refers specifically to the living part of a plant cell, excluding the cell wall; "progenitor" refers to an ancestor or a precursor in a lineage; and "protoplasm" is the living substance within a cell, including the cytoplasm and nucleus. These terms do not apply to the pre-cellular context in the same way that "protocell" does.