Question

1. humans are unable to digest cellulose. no animal, in fact, can digest cellulose with their own digestive enzymes. knowing this, predict what you think is actually responsible for digesting cellulose in a cows stomach. why?
2. propose a model for how what you identified in question 1 is able to break down cellulose (i.e. what bonds are broken, what type of reaction is taking place).
3. add the missing component to the diagram below to show the input needed for this reaction to occur.
4. cattle industries will often add antibiotics in their feed. what is the purpose of antibiotics? why might cattle industries use them? you may use online resources to research this.

Explanation:

Step1: Answer question 1

Cows have symbiotic bacteria in their rumen (a part of the stomach). These bacteria produce cellulase enzymes which can break - down cellulose. Animals lack the ability to produce cellulase on their own, but the bacteria in the cow's stomach can.

Step2: Answer question 2

Cellulose is a polysaccharide composed of glucose monomers linked by β - 1,4 - glycosidic bonds. The bacteria in the cow's stomach secrete cellulase enzymes. These enzymes catalyze a hydrolysis reaction, where water is used to break the β - 1,4 - glycosidic bonds in cellulose, breaking it down into smaller sugars like glucose.

Step3: Answer question 3

The missing component for the reaction to occur is water ($H_2O$). In a hydrolysis reaction, water is used to break the glycosidic bond in cellulose.

Step4: Answer question 4

Antibiotics are substances that can kill or inhibit the growth of bacteria. In the cattle industry, antibiotics are often added to feed to prevent bacterial diseases, promote growth (by reducing the energy the cattle spend on fighting off infections), and increase feed - efficiency. However, over - use of antibiotics can lead to the development of antibiotic - resistant bacteria.

Answer:

1. Symbiotic bacteria in the cow's rumen are responsible for digesting cellulose because they produce cellulase enzymes which animals cannot produce on their own.
2. Cellulase enzymes secreted by bacteria in the cow's stomach catalyze a hydrolysis reaction to break the β - 1,4 - glycosidic bonds in cellulose.
3. Water ($H_2O$) is the missing component.
4. The purpose of antibiotics is to kill or inhibit bacteria. Cattle industries use them to prevent diseases, promote growth, and increase feed - efficiency.