Cows can derive nutrients from cellulose because a. they produce enzymes that recognize the shape of the glucose-glucose bonds and hydrolyze them. b. they re-chew their cud to break down cellulose fibers. c. their digestive tract contains microorganisms that can hydrolyze the bonds of cellulose. d. they convert cellulose to starch and can digest starch.

Verified step by step guidance

1. Understand that cellulose is a complex carbohydrate composed of glucose units linked by β-1,4-glycosidic bonds, which are difficult for most animals to digest.
2. Recognize that most animals, including humans, lack the enzyme cellulase, which is necessary to break down these β-1,4-glycosidic bonds in cellulose.
3. Consider the role of microorganisms in the digestive systems of herbivores like cows, which can produce cellulase and other enzymes to break down cellulose.
4. Evaluate the options given: (a) Cows do not produce the enzyme themselves; (b) Re-chewing helps physically break down fibers but does not chemically digest cellulose; (c) Microorganisms in the cow's rumen produce cellulase, enabling cellulose digestion; (d) Cows do not convert cellulose to starch.
5. Conclude that the correct answer is related to the presence of microorganisms in the cow's digestive tract that can hydrolyze cellulose.

Key Concepts

Cellulose Digestion

Cellulose is a complex carbohydrate that forms the structural component of plant cell walls. Cows, as ruminants, have specialized digestive systems that allow them to break down cellulose through fermentation. This process is facilitated by microorganisms in their rumen, which produce enzymes capable of hydrolyzing the β-1,4-glycosidic bonds in cellulose.

Rumen Microbiota

The rumen is the first chamber of a cow's stomach, housing a diverse community of microorganisms, including bacteria, protozoa, and fungi. These microbes play a crucial role in breaking down cellulose and other complex carbohydrates, converting them into volatile fatty acids, which serve as a primary energy source for the cow. This symbiotic relationship is essential for the cow's ability to extract nutrients from fibrous plant material.

Cud Chewing (Rumination)

Rumination is the process by which cows re-chew their cud, which consists of partially digested food. This behavior aids in further breaking down cellulose fibers, increasing the surface area for microbial action in the rumen. By re-chewing, cows enhance the efficiency of their digestion, allowing for better nutrient absorption from fibrous plant materials.