The cells are generally not different, it's how they behave is what is significantly different. Yeast have phases they follow when conditions are met they move on.
Yeast like all organisms only want to reproduce. This is all they do. Prepare for and reproduce until they can't due to conditions. Then lay in wait until they can reproduce again.
Yeast reproduce by cell division budding. 1 Cell becomes 2 but the mother cell remains the same size feeding and growing the daughter until it releases. Sugar is the metabolic fuel the Cell needs to do this. Cell size, solution enviroment and colony size appears to be the division triggers. These new cells then take in chemicals and expel waste (eat and shit) to grow in size until they are ready to divide. The mother cell also continues to feed and may be ready to divide again before it's last daughter will.
New and old cell differences.
Bud Scars. When a cell divides a scar is formed at the separation point. These scars on the cell wall don't appear to have pathways like the rest of the healthy wall. So the more times a cell has divided the less viable surface area the cell wall has to take in chemicals. So they will do less work for a brewer compared to a new cell.
Lag, Exponential Growth, Stationary Growth.
These phases need to be viewed as a whole colony average. As each individual cell is just doing what it can to reproduce based on its environment, and not all cells are in the same state of reproduction. As the environment changes we see these phases manifest.
Row, Row, Row your boat RRRYB
This is a terrible analogy and may not translate well to other culters, but RRRYB is sung by a crowd with different groups starting at different times to make a perpetual canon but then sync up in catches.... Picture a colony of yeast as RRRYB but there's a finite amount of words (nutrients,o2, sugars etc) each new cell starts to sing at different times. These "catches" are the phases we see. Songs over once out of "words"
colony density flocullation is when cells stick together due to electrical charges. When a cell has a few other cells stuck to it, it's speculated that this triggers a life cycle phase for the cell to go dormant. Much like locus only swarm when the colony gets too big or dense, the the trigger is repeated contact from other locus. Its survival trigger, food will run out quickly so move on. With yeast they can't move on, so they wait, until they have oxygen or sugar again. Production of co2 helps physically separate cells giving the cell buoyancy, when sugar is limited co2 isn't produced and flocculation isn't defeated anymore.
When a cell is budding without enough oxygen, is when esters are produced. New cells birthed in a deprived environment are weaker, these cells have been observed at producing more esters than healthy cells as they bud thier daughters.
The difference in colony is how many cells you have of a specific age. Older cells having stronger cell walls but more bud scars.
Ester control is all about how much yeast, oxygen, nutrients, sugar there is.
Manipulate esters by controling the oxygen free window of time before flocculation.