This area, indicated by the arrow, of the endoplasmic reticulum (er) is involved in

The answer is synthesis of proteins. The endoplasmic reticulum assists many general functions, containing the folding of protein molecules in sacs called cisternae and the transport of synthesized proteins in vesicles to the Golgi apparatus. This takes two steps: transcription and translation. 

the cells uses some of the atoms of the glucose molecules to atp molecules. the atoms of the glucose molecules will then be converted into energy which will be eventually stored in atp. the energy produced which are stored in atp are coming from the glucose’s chemical bonds.