Tag: bio-chemistry
Questions Related to bio-chemistry
Which one of the following pairs of the cells with their secretion is correctly matched?
-
Oxyntic cells- A secretion with pH between 2.0 and 3.0
-
Alpha cells of Islets of Langerhans- Secretion that decreases blood sugar level
-
Kupffer cells- A digestive enzyme that hydrolysis nucleic acids
-
Sebaceous glands- A digestive enzyme that hydrolysis nucleic acids
Oxyntic cells or parietal cells, are the stomach epithelium cells that secrete gastric acid intrinsic factor. These cells secrete hydrochloric acid (HCl), which makes the gastric juice acidic (pH =2 -3).
Where is protein digestion accomplished?
-
Stomach
-
Ileum
-
Rectum
-
Duodenum
Protein digestion occurs in stomach, duodenum, jejunum and ileum. It is completed in ileum.
The organ that stores bile is
-
Pancreas
-
Liver
-
Gall bladder
-
Spleen
The digestive role of the liver is to produce bile and export it to the duodenum. The gall bladder primarily stores, concentrates and releases bile.
Digestion of both starch and protein is carried out by
-
Gastric juice
-
Gastric lipase
-
Pancreatic juice
-
Ptyalin
Enzyme lactase occurs in
-
Saliva
-
Pancreatic juice
-
Intestinal juice
-
Stomach
Which of the following best represents the enzyme composition of pancreatic juice?
-
Amylase, peptidase, trypsinogen, rennin
-
Lipase, amylase, trypsinogen, peptidase
-
Lipase, amylase, pepsin, maltase
-
Peptidase, amylase, pepsin, rennin
Pancreatic juice is liquid secetrted by pancreas . It is alkaline in nature and it has following enzymes lipase, for digesting fats, amylase for digesting starch, trypsinogen for digesting proteins.
The end products of protein digestion are
-
monosaccharides
-
steroids
-
amino acids
-
fatty acids
- Amino acids and proteins are the building blocks of life. Amino acids are organic compounds that combine to form proteins.
- When proteins are digested or broken down, amino acids are left. Zymogenic cell or peptic cell in the stomach that releases pepsinogen and chymosin.
- This inactive pepsinogen, on exposure to hydrochloric acid, gets converted to the active enzyme pepsin.
- Pepsin is produced in the stomach and is one of the main digestive enzymes, which helps in digestion of the proteins to polypeptide chains. The end product of protein is it must be broken down into amino acids. Hence, the end product of protein digestion is amino acids.
A pancreatic zymogen secreted into the duodenum, can be activated by:-
-
trypsin
-
pepsin
-
secretin
-
chymotrypsin
Enteropeptidase is an enzyme produced by the cells of the duodenum and is involved in the digestion in humans and other animals. Enteropeptidase converts trypsinogen (a zymogen) into its active form trypsin, resulting in the subsequent activation of pancreatic digestive enzymes
If for some reason the parietal cells of the gut epithelium become partially non-functional, what is likely to happen?
-
The pancreatic enzymes and specially the trypsin and lipase will not work efficiently.
-
The pH of stomach will fall abruptly.
-
Steapsin will be more effective.
-
Proteins will not be adequately hydrolysed by pepsin into proteoses and peptones.
Parietal cells secrete HCl and intrinsic factor. Parietal glands also secrete pepsinogen to which hydrochloric acid acts to convert it into pepsin. Pepsin in return causes digestion of protein. If parietal cells become non-functional, it will directly affect protein digestion. So, the correct answer is (d).
When the acidic food from stomach comes to small intestine which of the following acts on it to make it alkaline?
-
Bile
-
Trypsin
-
Pepsin
-
None of the above
- The pancreatic enzymes and intestinal enzymes are optimally active in alkaline pH (8.0-8.4) in the small intestine.
- Thus, the acidic food from stomach is made alkaline by the action of bile.
- Bile is alkaline in nature as it contains organic salt known as bile salt.