What kinds of factors regulate a cell's progress through the cell cycle?

Phosphorylation, Cdks signal the cell that it is ready to pass into the next stage of the cell cycle.  Cdks means: Cyclin-dependent protein kinases  

Glucose, also called grape sugar, blood sugar or corn sugar, is among the simplest and one of the primary naturally occurring sugars. produced naturally by plants as the primary photosynthesis product, it is heavily used by living beings as a main energy source and is necessary for cellular respiration. chemically, it is a monosaccharide carbohydrate and serves as a building block for complex sugars like starch.