These are yeast cells. They ferment the sugars in grapes and produce the alcohol in wine. But that isn't the whole story. Wine is more than just alcohol.
Grape-vine leaves capture the Sun's energy (energy from the cosmos) and package it tightly into grape sugars. The vines use some of that sugar energy to manufacture and incorporate, through complex biochemistry, the universe of ingredients that we find in mature grapes. Those ingredients are the foundation for the enormous array of delicate and distinct wine varieties and vintages that we celebrate.
Now here's the water into wine part. The sugars in grapes are made from just two ingredients, carbon dioxide and WATER. Well not all of the water. Water is made up of two parts hydrogen and one part oxygen, H2O. To make sugar, the hydrogen in water must become available and combined with carbon dioxide. Grapevine leaves use the Sun's energy to strip the hydrogen atoms out of water molecules making them available for combination with carbon dioxide. Without water we wouldn't have wine. By the way, you are breathing the leftover from this stripping process—oxygen!
Why is wine making a cosmic event? Remember the central cosmic theme? The Universe figures out the best ways of dispersing energy and matter. Wine making transforms grape "matter and energy" into a less tightly packaged form of grapes, a liquid form that begs to be dispersed further. Wine drinking is the final rendering of grape matter and energy back to the starting point. If you've had a glass of wine recently, some of your breath is dispersing the carbon dioxide and water that once was "grape."
Wine making and wine drinking are expressions of the same cosmic force that guides the genesis stars and candle flames!