I think it is fossil fuel .. might be wrong tho
Carbohydrates are made from the process of photosynthesis by green plants by use on energy from sunlight. They have various functions in the ecosystem by plants an animals. The two main function of carbohydrates are; carbohydrates as a source of energy for cellular activities. They are reserves and stored in form of starch in plants and inform of glycogen in animals. They also act as structural components in both plants and animals such as cellulose which is a components of plant cells.
The endoplasmic reticulum can either be smooth or rough, and in general its function is to produce proteins for the rest of the cell to function. The rough endoplasmic reticulum has on it ribosomes, which are small, round organelles whose function it is to make those proteins.