What is the function of the endoplasmic reticulum in a cell? A. converting energy from food into a form the cell can use
B. assembling lipids, proteins, and other materials for export out of the cell
C. providing a barrier between the cell and its surroundings
D. packaging proteins and other materials from the endoplasmic reticulum for storage in the cell or transport out of the cell

B its main function is to make proteins and lipids

the sugar-phosphate backbone forms the structural framework of nucleic acids, including dna and rna. this backbone is composed of alternating sugar and phosphate groups, and defines directionality of the molecule.

image result for how many calories of energy will 20 grams of carbohydrates provide in one gram provides 4 calories

consuming the right balance of protein, carbohydrates and fat can you maintain a healthy weight and optimize your energy levels. protein and carbohydrates both contain 4 calories per gram, while fat provides 9 calories per gram.