Chapter 18, Problem 1aCP

Summary Introduction

To review:

1. The terms digestion and absorption.

2. The process of digestion of molecules along with the molecules that are absorbed.

Introduction:

Food is necessary for the life cycle and well being of an organism. Each organism needs food for its survival as well as existence. Most of the organisms consume food as complex polymers, which are then broken down by the organisms into their monomers in order to get utilized in the body. Every class of organism has a different level of system for the digestion and utilization of food.

Explanation of Solution

Digestion: The process of breakdown of food into their smaller subunits is referred to as the digestion. The body is unable to digest the food in its polymer form thus, digestion is necessary for the utilization of food.

Absorption: The process by which digested food gets absorbed into the blood and lymph is referred to as absorption. The absorbed food is transported throughout the body in the blood and lymph.

There are various enzymes present throughout the alimentary canal for the digestion of food. The glands associated with the alimentary canal also secrete several enzymes for the digestion of food. The digestion of the food starts in the mouth. The major site for protein digestion is the alimentary canal. The digestion of lipids occurs in the small intestine. The final digestion of all food materials takes place in the small intestine.

The monomers of ingested food get absorbed in the blood or lymph. The polymers of fat are converted into the fatty acids and glycerol that are absorbed in the lymph. The polymers of the protein molecules are broken down into the amino acids that are absorbed in the blood from the blood capillaries present in the small intestine. The polymers of carbohydrates are broken down into the glucose that is also absorbed in the blood from the capillaries present in the small intestine.