Question

1. Explain how digested fats are absorbed and transported in the body including the health effects of the different types of lipoproteins. Include the following terms in your explanation: lipoproteins, chylomicrons, HDL, LDL.

2. Explain how fat is digested including the 3 enzymes that assist in digestion, the function of bile, and which part(s) of the GI tract fat digestion takes place.

Answer 1

1.Absorption and Transportaion into blood

Major products of lipid digestion are fatty acids and 2 monoglycerides enter the enterocyte by simple diffusion across the plasma membrane.A considerable fraction of fatty acids also enter the enterocyte via a specific fatty acid transporter protein in the membrane.

Lipis are transported from enterocyte into blood by a mechanism distinctly different from what we have seen for monosaccharides and amino acids.

Once inside the enterocyte, fatty acids and monoglyceride are transported into the endoplasmic reticulum,where they are used to synthesize triglyceride.Beginning in the endoplasmic reticulum and continuing in the Golgi triglyceride is packaged with cholestrol,lipoproteis and other lipids into particles called chylomicrons.

Chylomicrons are extruded from Golgi into exocytotic vesicles,which are transported to the basolateral aspect of the enterocyte.The vesicles fuse with plasma membrane and undergo exocytosis,dumping the chylomicrons into the space outside the cells.

CHOLESTROL(GOOD AND BAD)

Two types of lipoprotein to and from cells

1.Low Density Lipoprotein (LDL)

2.High Density Lipoprotein(HDL)

LDL cholestrol considered as bad cholestrol,beacause it contributes to fatty buildup in arteries ,that will result in Atherosclerosis.

HDL can be thought as good,its higher level actually better for body.

Health effects of high lipoproteins in the body will results in Heart attack.That comes from Atherosclerosis.Regular exercises are neccessary to control lipoprotein with in the body.

2.Fat digestion

The process of Fat digestion involves a series of steps that begin from the moment food enter your mouth.It includes the following.

1.Mouth

The digestion process begins when you start chewing your food.Your teeth breaks food into smaller pieces,saliva moistens the food so that it is easier for the food to move throgh your esophagus and into your stomach.

2.Esophagus

when you swallow a series of muscle contraction called Peristalsis move the food throgh esophagus into your stomach.

3.Stomach

Your stomach lining produces acids and enzhymes that breakdown your food further so that foods can pass to small intestine.

4.Small intestine

Majority of fat digestion happens once it reaches the small intestine.This is also where the majority of nutrients are absorbed.your Pancreas produce enzhymes that breakdown fats,carbohydrates and proteins.

Liver produces bile that helps in digest fats and certain vitamins.The bile is stored in gallbladder.These digestive juices are delivered to small intestine throgh ducts where it all work together to complete fat breakdown.

MOST OF THE FAT DIGESTION OCCURS AT SMALL INTESTINE OF GI TRACT

Most effectve enzhyme in fat digestion are Lipase,Amylase and Ox bile.Enzhymes produce chemical reactions in the body.They speed up the chemical reaction in the body.They helps in breakdown of food particle for digestion.