Digestion and Absorption Test - 76

Sugars are digested and absorbed to provide your body with its greatest source of energy. During digestion, complex sugars are broken down into monosaccharides and absorbed into the bloodstream. Monosaccharides, the simplest sugars, include glucose, galactose, and fructose. Digestion occurs in the mouth, stomach, and intestine.

Rabbits are herbivorous animals. The digestive system is made up of an  oesophagus, stomach, and intestinal tract like other mammals. However, since their intake consists large quantities of fibre, rabbits are characterised by hind gut fermentation similar to horses. This helps to break down the indigestible materials into their chemical form. The presence of villi in the intestine distinguishes it from the stomach.

The oral cavity is made up the alveolar arches, teeth and gums, and palate and tongue which is situated in the floor of the mouth, and is attached by muscles to the hyoid bone, mandible, styloid processes, and pharynx. The underside of the tongue is connected to the floor of the mouth by a median fold of mucous membrane, the frenulum.

Maltose is a disaccharide formed by the union of two glucose units (monosaccharide). Maltose is produced when amylase breaks down starch. In humans, maltose is broken down by the enzyme maltase. Pepsin is a proteolytic enzyme. It acts on proteins. So, maltose and pepsin is a wrong match.

Solution

Correct answer is option B

Explanation for correct option:

• Succus entericus, also called as intestinal juice, contains mucus and digestive enzymes, including enteropeptidase, lactase, and sucrase.
• Succus entericus is the alkaline secretion produced by glands in the duodenum wall of small intestine, specifically by crypts of Lieberkuhn. 

The gastric juice is made up of hydrochloric acid, pepsinogen and other digestive enzymes, intrinsic factor, gastrin, mucus, and bicarbonates. It has a pH ranging from 1 to 3. Its low pH is essential in activating many digestive enzymes and in destroying various pathogens. Thus, the correct answer is option C.

Ampulla of Vater is also known as hepatopancreatic duct because it is the junction which joins the gallbladder duct and pancreatic duct to form common bile duct. It is mainly located at the major duodenal papilla.

The ileum is the last part of the small intestine and extends into the large intestine. It measures around 2 to 4 m in length. Ileum consists digestive glands which secrete enzyme for further digestion. Jejunum and ileum both have the presence of villi on their muscular walls which give them an extra surface area for absorption of nutrients. Digestive systems final process is completed here during which the liquid and food particles are broken into nutritional components. When this digestive blend moves through ileum of the small intestine, the nutrients are absorbed by villi and transferred them to bloodstream and liver.

• The digestion of starch begins with the action of salivary alpha-amylase/ptyalin. 
• The starch is further digested in the small intestine in the presence of pancreatic amylase. 
• Pancreas secretes lipase enzyme and liver secretes bile salts. in the presence of bile and pancreatic lipase, fat is emulsified and digested in the small intestine. 
• Protein digestion first starts in the stomach in the presence of pepsin enzyme. 
• Trypsinogen and chymotrypsinogen are produced in the pancreas which are inactive(zymogenic) proteases that, once activated in the duodenum gets converted to active trypsin and chymotrypsin further digest the protein into simple amino acids. 
• Chymosin, known also as rennin, is a proteolytic enzyme synthesized by chief cells in the stomach that curdle milk by transforming caseinogen into insoluble casein. 

Enzymes are biological catalyst. while the first enzyme molecule that was extracted was urease. However, as of now since 1930 to 1936 pepsin, chymotrypsin and trypsin has been isolated and crystallized. However, the enzyme that can act in acidic medium is pepsin.
Therefore, the correct answer is option A.