Question

Describe the types of chemical digestion (including bile function, although that is not always put into this category) that take place along the length of the GI tract. Where do the different types of chemical digestion and bile action take place and what do they achieve?

Answer 1

Chemical digestion involves breaking down the food into simpler nutrients by action of chemicals (Enzyme)

1.Chemical Digestion in Mouth-

Chemical digestion starts in the mouth when food mixes with Saliva.

Saliva Contain 2 Enzymes that aid in digestion-

1.Salivary Amylase(Ptyalin)

2.Lingual Lipase

Starch---------------------------Maltose and Dextrin(Simple sugars) by Salivary Amylase

Lipids---------------------------Diglycerides by Lingual Lipase

Esophagus have no Chemical Digestion.

Chemical Digestion in Stomach---

Digestive Enzyme secreated in Stomach is Pespsinogen(Inactive).Pepsinogen is secreated by Chief cells of Stomach.When protein containing Food Reaches stomach Hcl is released ,Hcl converts Pepsinogen --------Pepsin(Active form)

Proteins------------------------Polypeptides by Pepsinogen.

Digestion in Small Intestine .

Bile secreated By liver------Hepatic duct---Gall bladder-----Cystic duct---Common Bile duct (formed by Combining cystic duct and Hepatic duct)

Pancreas-------Pancreatic duct.

Pancreatic duct Joins with common bile duct to form Common hepatopancreatic duct that opens into Duodenum.Through this,Pancreatic enzymes and Bile reach Duodenum.

Pancreatic Enzymes-

a)Pancreatic proteases (such as trypsin and chymotrypsin)

b) Pancreatic amylase

c)Pancreatic lipase

d)Deoxyribonuclease and ribonuclease

Fats-----------------Emulsification(Breakdown into Tiny Droplets) by Bile

Starch-----------------------------Maltose(Pancreatic and Intestinal Amylase)

Triglycerides--------------------------------Glycerol + Fatty acid by Pancreatic and Intestinal lipase

Peptides-------------------------------------Aminoacid by Peptidases

DNA/RNA---------------Nucleosides by Nuclease