Cellulose, chitin, and peptidoglycan are all considered as
carbohydrates. Now in the molecular level of these carbohydrates, structural polysaccharides exist as sets of long, parallel
strands that are linked to one another. Due to this arrangement, pulling
and pushing forces are being withstand.
The process in which oxygen atoms are made available to the cell of animals is called cell respiration. In cell respiration the food molecules undergo process which is called food oxidization, that make it available to be absorbed by the animal cell.