“How to make a cell” can mean several different things, and the answer depends on what you’re after. If you’re building a model for a school project, you need some common household materials and a basic understanding of organelles. If you’re curious about how your body makes new cells, that’s a tightly controlled process called cell division. And if you’re wondering how scientists are trying to build cells from scratch in the lab, that’s one of the hardest unsolved problems in biology. This article covers all three.
Building a Cell Model for School
A 3D cell model is one of the most common biology assignments, and the easiest version uses food. You need two sandwich-sized zip-lock bags, a hard plastic container roughly the same size, two boxes of light-colored Jell-O (lemon works well), and an assortment of fruits or candy to represent the organelles inside the cell.
The Jell-O acts as the cytoplasm, the gel-like fluid that fills a real cell. Pour it into one of the zip-lock bags. The bag itself represents the cell membrane, the thin barrier that controls what enters and exits. If you’re modeling a plant cell, place the bag inside the hard plastic container, which stands in for the rigid cell wall that plant cells have but animal cells don’t. Then refrigerate it until the Jell-O is partially set but still soft enough to push things into.
Once it firms up slightly, add your organelles. Here’s a simple guide:
- Nucleus: A large grape or plum. This is the control center holding the cell’s DNA.
- Mitochondria: Kidney beans or jelly beans. These are the cell’s power generators.
- Endoplasmic reticulum: Fruit roll-ups or ribbon candy, folded into layers. This network manufactures proteins and lipids.
- Golgi apparatus: Stacked flat candy like fruit leather strips. It packages and ships molecules around the cell.
- Ribosomes: Sprinkles or small cake decorating beads. These tiny structures build proteins.
- Vacuole: A water balloon or large gummy bear. Plant cells have one large central vacuole for storage; animal cells have several smaller ones.
- Lysosomes (animal cells only): Small round candies like Gobstoppers. They break down waste.
- Chloroplasts (plant cells only): Green candies or grapes. These convert sunlight into energy.
Push each piece into the Jell-O, return it to the fridge, and let it set completely. Label each organelle on a card or directly on the model for your presentation.
How Your Body Makes New Cells
Your body doesn’t build cells from raw parts. It copies existing ones through cell division, a process where one cell splits into two genetically identical daughter cells. The full cycle, from the moment a cell is born to the moment it divides, involves several phases that coordinate DNA replication with physical separation.
Most of the cycle is spent preparing. During the growth phases (G1 and G2), the cell increases in size and produces the proteins it needs. During S-phase, it copies all of its DNA. These early phases are highly variable in length. Some cells rush through them, others take their time, and the duration can differ significantly even among cells of the same type.
The actual division, called mitosis, is the short and remarkably consistent part. Research using live cell imaging has shown that while the earlier phases vary widely from cell to cell, the duration of mitosis stays nearly constant and doesn’t seem to be affected by how long the earlier phases took. This consistency is maintained by a built-in feedback loop: the key molecular switch that triggers division also activates its own activator and shuts down its own inhibitor, creating a kind of self-reinforcing cascade that keeps the timing tight.
Cells also have built-in checkpoints, essentially quality control gates that prevent a cell from moving to the next phase until the previous one is properly finished. One critical checkpoint verifies that all chromosomes are correctly attached before the cell physically splits. These safeguards are what keep your DNA intact across billions of divisions over a lifetime.
How Scientists Build Cells From Scratch
Creating a living cell in the lab, entirely from non-living components, is something no one has fully achieved. But researchers have made significant progress on two fronts: stripping natural cells down to their bare essentials, and assembling cell-like structures from the bottom up.
The Top-Down Approach: Minimal Genomes
One landmark project systematically removed genes from a bacterial genome to find out how few are needed for life. The result was a synthetic organism called JCVI-syn3.0, which contains just 473 genes packed into a genome of 531,000 base pairs. That’s far smaller than any naturally occurring free-living organism.
Of those 473 genes, about 48% handle reading and copying genetic information. Roughly 18% manage the structure of the cell membrane, and another 17% run the cell’s basic metabolism. The remaining 17%, a total of 79 genes, have no known function. Scientists know the cell dies without them, but not what they actually do. That gap is a humbling reminder of how much basic biology remains unknown.
Earlier theoretical estimates had predicted that life could run on as few as 206 to 256 genes. Experimental testing pushed that number much higher. Work on the bacterium with the smallest known genome of any independently growing organism identified 387 essential protein-coding genes plus 43 genes encoding structural RNA molecules, suggesting that real-world complexity exceeds what computational models predict.
The Bottom-Up Approach: Assembling Parts
Rather than simplifying an existing cell, some researchers are trying to build one from components that were never alive. The basic strategy involves creating a tiny membrane bubble (essentially a synthetic cell membrane), then loading it with the molecular machinery needed for life.
One technique uses microfluidic devices, chips with channels thinner than a human hair, to generate stable, uniformly sized membrane compartments. These artificial shells can then be injected with purified proteins, including membrane proteins and structural proteins that give real cells their shape, using a precision injection method that delivers trillionths of a liter at a time.
The energy problem is one of the trickiest parts. Real cells run on a molecule called ATP, and they constantly produce it. Researchers have powered synthetic cells using light-activated pumps embedded in the membrane alongside the natural molecular turbine that generates ATP. In 2019, a team managed to produce ATP without that turbine at all, instead using a synthetic chemical pathway fueled by the amino acid arginine. Neither approach yet produces energy reliably enough to sustain ongoing cellular activity.
Getting these systems to read DNA and build proteins is another active challenge. Scientists have assembled the transcription and translation machinery, either from cellular extracts or from individually purified components, and placed it inside membrane compartments. Some of these engineered cell-like systems can process information, move on their own, communicate with neighboring compartments, and even interact with living cells. But self-sustaining replication, where a synthetic cell copies all of its own parts and divides, remains out of reach. Achieving that would require the cell to manufacture its own protein-building machinery, synthesize its own membrane lipids, and copy its own DNA, all simultaneously and in balance.
Turning Stem Cells Into Specific Cell Types
There’s one more meaning of “making a cell” that’s worth knowing about: directing stem cells to become a particular cell type. This is central to regenerative medicine and disease research.
Induced pluripotent stem cells (iPSCs) are adult cells that have been reprogrammed back to a flexible state, capable of becoming almost any cell type. To push them toward a specific fate, researchers expose them to carefully timed sequences of chemical signals that mimic the cues a developing embryo would provide.
To make sensory neurons, for example, one approach blocks two specific signaling pathways for the first five days, nudging the cells toward a nerve cell identity. Then a different set of three small molecules is added from day 2 through day 10 to steer them toward the peripheral nervous system. From day 10 onward, the cells are bathed in a cocktail of nerve growth factors and nutrients that help them mature into functional neurons. The whole process takes a few weeks, and the exact cocktail and timing differ depending on the target cell type. Getting the sequence wrong produces the wrong cells, or no viable cells at all.
This technology is already being used to grow patient-specific cells for studying diseases, testing drugs, and developing transplant therapies. It doesn’t create cells from nothing, but it does let researchers produce cell types that would otherwise be impossible to obtain from a living patient.