Cytosol

Cytosol is a cell’s energy and its health in one number. Every cost the cell pays and every injury it takes come out of the same number, and when that number sits at its floor long enough the cell dies, whatever put it there. Nothing has a separate wound track. The inspector reads cytosol as a percentage of that cell’s own maximum, so two cells showing the same figure are not holding the same amount.

Death

Cytosol at or below the death threshold starts a starvation timer, and the cell dies when that timer passes its grace window. Feeding does not reset the timer: it winds back down at the rate it wound up, so a cell that is net negative and finds one mouthful per window does not escape. Only sustained recovery, more time off the floor than on it, clears it.

The inspector warns earlier. The bar reddens and the verdict reads STARVING below 25% of the cell’s own maximum, which is a caution and not the level anything dies at.

The death is then labelled from what dominated the run-up:

• Senescence wins outright once the cell is far enough into the window that opens at senescence onset, roughly 71% of the way through it.
• Otherwise heat, cold, acid, alkali or predation, whichever damage source led the recent moving average, and only when it led by more than a noise threshold. Toxin is booked to predation.
• Starvation is what is left when nothing led.

Some deaths do not wait on the timer. Temperature past the absolute heat or cold threshold kills instantly. A digestive enzyme hit that takes the cell to the death threshold kills on the spot. A split whose halves would land a daughter at or below that threshold kills the parent.

Constant drains

Charged every second the cell is alive and not mid-division:

A genome carrying a longer lifespan multiplier buys that life by paying proportionally more on the organelle, collector and size terms. The base rate and the pH vacuole charge are not scaled by it.

Environmental damage sits on top. Ground outside the band the cell’s temperature and pH tolerance genes describe drains the pool continuously, scaled by membrane permeability. So do toxin, digestive enzymes, antibodies, viral and bacterial infection, and another cell’s cilia or flagella in contact. All of it comes out of the one pool.

Drifting is free. The locomotion drain was removed from both the shader and the CPU cilia path, so a cell at speed pays nothing for moving, with or without cilia. Only bursts cost: while the sprint timer is running the cell is charged a second copy of its maintenance cost per second, meaning base, organelle, collector and size, but not the pH vacuole or senescence charges. A flagellum’s burst and its sustained cruise check the pool first on the CPU and are refused if it cannot cover them.

Cytosol income

Mitochondria are the main income. Each draws nutrient out of a vacuole and converts it, less a flat waste fraction that leaves the cell as particles.

There is no penalty for stacking them: the tenth mitochondrion converts at the same rate as the first, and the same holds for collectors and for vacuole feeding. What bounds a large stack is supply, because every mitochondrion in the cell competes for the same vacuole storage.

Conversion throttles down as the pool approaches full, and the vacuoles then accumulate toward the nucleus for division instead. Throughput also rises with how full the cell’s own stores already are, so a well-fed cell converts faster. A cell outside its thermal band keeps eating at the same rate but converts less of it: cold and heat cut the yield, not the appetite.

A cell with no mitochondria at all is not finished. It drains its own vacuoles straight into the pool, at a fraction of the normal rate, and pays extra waste heat per unit delivered.

Cytosol also arrives without passing a mitochondrion:

• Engulfment. An amoeba pays a running cost to wrap and digest its prey. When it finishes it takes whatever the prey had left and adds the prey’s whole maximum to its own ceiling for good.
• Slime mold equalisation. Connected slime mold cells equalise, cytosol flowing from fuller to emptier by the gap between each cell’s own percentage rather than by absolute amount, and nothing moves until that gap exceeds two points.
• Phase change refund. Suppressing a gene copy at a cell-cycle phase change refunds half that organelle’s structural build cost, but not its stored contents, which go back to the substrate as nutrient particles. Copies the new phase expresses are regrown at full cost, so a phase change is normally a net loss.
• Symbiotic enzymes. A digestive enzyme carrying the symbiotic modifier restores cytosol to the cell it lands on instead of damaging it.

Cytosol capacity gene

One gene sets three things, each mutating separately and each clamped:

It is single-copy, never duplicates, and is lost outright at a 0.5% chance per division. Amoeba engulfment and a slime mold network each raise the ceiling further, on top of the gene.

A bigger tank is mostly not shelter. Environmental drain scales with the width of the cell’s own capacity span, and an enzyme hit is a fixed fraction of that span, so a large-capacity cell takes proportionally larger hits. The environmental term stops scaling once that span reaches 10, so an extremely large tank does begin to dilute pH and heat damage; enzyme hits keep scaling with no ceiling. Age is not diluted either, because the senescence bleed is a fraction of the cell’s own maximum: a large tank and a small one of equal lifespan reach the same end at the same age. What capacity buys is time between meals.

An enzyme does nothing at all to a cell with no pH tolerance gene. The damage routine reads that gene first and returns when it is absent.

Division cost

A division is paid for twice, once when it is triggered and again when the cell splits, and which trigger fired decides the first charge. A division called by the cell’s behaviour network, or by the player, pays the base per-daughter cost twice over, scaled only by the gene’s cost multiplier. The automatic trigger, which runs only on cells that have no behaviour network, scales that same cost against capacity as well: a small-tank genome pays up to 2.5x the base, a large-tank one as little as 0.5x. When that trigger fires from the cell’s own per-frame check rather than on the GPU’s ready flag, it adds a tax on every organelle the parent carries.

No trigger fires if paying for it would put the cell under its floor.

At the split the pool is halved: each daughter takes half the parent’s remainder, measured from the floor rather than from zero when the parent is already negative. If that half would land at or below the death threshold the split aborts and the parent dies instead.

While a division runs, upkeep and every source of cytosol income are frozen. Environmental damage is not, so a lethal field still kills a cell mid-split, and a divider that was already net negative before the freeze is reaped as insolvent rather than sitting out its division forever.