Because they do not have the digestive enzyme to break down cellulose.
It is Cellulose
Humans can digest starch because they produce an enzyme called amylase that can break down starch into simpler sugars. However, humans lack the enzyme needed to break down cellulose, which is a complex carbohydrate found in plant cell walls. This is why humans cannot digest cellulose.
No, humans cannot digest cellulose, a key component of plant cell walls, because we lack the necessary enzymes to break it down.
No, humans cannot break down cellulose and utilize it as a source of energy because they lack the necessary enzymes to digest cellulose effectively.
No. Tissues are made of paper which is made from cellulose which humans cannot digest.
Paper is made of cellulose and humans cannot digest cellulose. Cellulose is another name for wood fiber.
Humans can't digest roughage (eg. cellulose) because of the beta linkages that hold the glucose molecules together. Humans don't have enzymes that can break these linkages.
Celulose. Some humans also cannot digest lactose aka someone who is lactose intolerant.
People cannot digest cellulose
Humans can't digest cellulose.
The cell walls of plants are made of cellulose. Approximately 33 percent of all plant material is cellulose. Humans cannot digest cellulose, but animals such as cows and horses can digest cellulose for food.
Complex answer: Cellulose is a polysaccharide that provides structural support for plants. Humans cannot digest cellulose. Thus, you cannot digest wood, which is mostly cellulose. :Simple answer Humans cannot digest the carbohydrate cellulose. Soures:AP biology class, Textbook :3