Why are all of the organs in the alimentary canal important in digesting food? as food passes through each organ, different hormones are produce to break it down so that our body can easily absorb nutrients. each organ has the same role in digesting food but is necessary in order to efficiently break food. the human body needs a long time to digest food in order to be able to absorb nutrients.

First choice.
You can refer to any bio book to simply give you a brief summary for what each organ do and what juices each organ produce to digest what specific typr of material in your food.

Proteins are the workhorses of the cell, controlling virtually every reaction within as well as providing structure and serving as signals to other cells. proteins are long chains of  amino acids  , and the exact sequence of the amino acids determines the final structure and function of the protein. instructions for that sequence are encoded in  genes  . to make a particular protein, a messenger ribonucleic acid (mrna) copy is made from the gene (in the process called  transcription  ), and the mrna is transported to the  ribosome  . protein synthesis, also called  translation  , begins when the two ribosomal subunits link onto the mrna. this step, called initiation, is followed by elongation, in which successive amino acids are added to the growing chain, brought in by transfer rnas (trnas). in this step, the ribosome reads the  nucleotides  of mrna three by three, in units called  codons  , and matches each to three nucleotides on the trna, called the anticodon. finally, during termination, the ribosome unbinds from the mrna, and the  amino acid  chain goes on to be processed and folded to make the final, functional protein

The reactants are co_{2} aka carbon dioxide and h_{2}o aka water along with light energy