3. Explain the digestion of a bite of mixed feed in a cow and a pig. Do this in a stepwise progression beginning with prehension and ending in defecation.

Answer and Explanation:

The process which our body uses to absorb and breakdown nutrients stored in food are called digestion. The cow has a unique digestive process to break down the food. It has four stomachs. When a cow takes a bite of food, it chews the food very little and then swallow. The reticulum and the rumen are the first two cats' stomach; the unchewed food travels to these stomachs—the food stored in this two stomach until later. Cow rests when this process of eating is completed. Later, cow coughs up unchewed food bits named cuds and chewed it thoroughly before swallowing again. The omasum and abomasum are the third and fourth stomach of a cow. The cuds then go to them, where it is completely processed. Some digested food enter in the bloodstreams, while rest goes towards the nourishment of cow. In the pig, the digestion of food starts in the mouth. Food is masticated into small pieces and mixed with saliva, then swallowed. After swallowing the food, it moves down into the stomach. In the stomach, food mixed with enzymes which help in the breakdown of the food. The food enters in the small intestine, where most of the digested food is absorbed. Then the food enters the large intestine. Large intestine absorbs salts and water from undigested material and get rid of left-over.

cellular respiration oxidizes food into energy in the form of atps.

glycolysis (6 c hexose) > 2x atps are used > 6c hexose biphosphate > 2 x 3c triphosphate >

2 x 3c pyruvate (2x nadh produced from nad) and (4x atp produced)

pyruvate actively pumped mitochondrial matrix.