MCQ Tutorial - Digestion and absorption of carbohydrate, protein and lipids

Regarding carbohydrate

• Lactose is milk sugar

• Sucrose is reducing sugar

• Fructose is table sugar

• Glycogen are polymers of α -D-Glucose

• Cellobiose is repeating disaccharide in cellulose

Regarding digestion of carbohydrate

• Digestion starts in stomach

• Ptyalin requires chloride for its activation

• Amylopsin is carbohydrate spitting enzyme

• Lactose is hydrolysed to glucose and galactose

• Sucrose is hydrolysed to two glucose molecules

Regarding carbohydrate absorption

• Disaccharides are absorbed directly into the blood stream

• Galactose are absorbed more rapidly than glucose

• Glucose & galactose are absorbed by active transport mechanism

• Fructose is absorbed by facilitated absorption

• Absorption occurs in small intestine

Glucose transporters

• GLUT-1 -glucose uptake is independent of insulin

• GLUT-2 -located in liver and kidney

• GLUT-3 -located in brain kidney and placenta

• GLUT-4 -function as insulin stimulated glucose uptake

• GLUT-5- red blood cell, brain and kidney

Factors influencing rate of absorption of carbohydrate include

• Absorption is decreased in deficiency of B1 B6 & B7

• Insulin has no effect on its absorption

• Inherited enzyme deficiency interferes with absorption

• Adrenocortical hormone deficiency increases absorption

• Thyroid hormone decreases the absorption of glucose from GI Tract

clinical manifestation of lactose intolerance include

• abdominal cramps

• distensions

• diarrhoea

• constipation

• flatulence upon ingestion of dairy products

Regarding lactose intolerance

• Bacteria act on Undigested lactose to form CO2&H2 gas

• Diagnosed with hydrogen Breath Test

• Benedict’s test with Urine is negative

• In primary type: gene for lactose is translated to form enzyme

• In Secondary type: occurs because of mucosal damage

Tags

NGSS.HS-LS3-2

Regarding Amino acids

• Phenyl alanine is essential

• Valine is essential

• Histidine is semi essential

• Tyrosine is non-essential

• Arginine is semi essential

Biologically active peptides include

• Thyrotropin releasing hormone (TRH) is a tripeptide

• Glutathione is a tripeptide

• Oxytocin is nonapeptide

• Vasopressin is nonapeptide

• Surfactant is pentapeptide

Regarding digestion of proteins

• Trypsin is secreted by pancreas as zymogen

• Large peptides and few amino acids are products of protein hydrolysis

• Pepsinogen are activated by autocatalysis

• Most of the digested protein are absorbed in intestine as polypeptides

• Enterokinase activate pancreatic zymogens