What is Cellulose?
Cellulose is a natural, linear polymer made of glucose units. It is a major component of the cell walls of most plants and is also found in some algae and bacteria. Cellulose comprises around 33% of all vegetable matter and is the most abundant of all naturally occurring organic polymer on Earth. The glucose units in cellulose are connected in a unique way (beta‐linkages) to make cellulose very resistant to breakdown. Mammals lack the enzymes required to break these beta‐linkages, required to release the glucose. But, bacteria, fungi, and protozoa that reside in the rumen of ruminant animals do possess the enzymes necessary to break those glycosidic bonds. Herbivores also possess the same microbes that can break down cellulose, but they are located in a different part of the gut known as the cecum. The relationship between microbes and herbivores is called a symbiotic relationship.
Also Read: Carbohydrates
Cellulose In Digestion – Herbivores, Termites, & Ruminants
Cellulose is a type of fiber that cannot be digested by the human digestive system. The presence of beta-acetal linkages in cellulose distinguishes it from starch and determines its digestion. The organisms that are capable of digesting the cellulose with their cellulase enzyme are microorganisms such as bacteria, fungi, and protozoa.
Except for a few multicellular organisms, such as termites, most higher organisms cannot digest cellulose without the help of microorganisms. In this article, we will discuss cellulose in digestion and why humans can digest starch but not cellulose.
Table of Content
- What is Cellulose?
- Structure of Cellulose
- Cellulose Digestion in Ruminants
- Cellulose Digestion in Termites
- Cellulose Digestion in Herbivores
- Reasons Why Humans Cannot Digest Cellulose
- Importance of cellulose in digestion