(a) Name the main organs of the human digestive system. Also name the associated glands
(b) How do carbohydrates, fats and proteins get digested in human beings ?

Explanation

Digestion of carbohydrates starts from
Buccal cavity the food receives saliva in the buccal cavity, which contains salivary amylase , It breaks down starch into simple (glucose) suger
Starch and glycogen `overset("Amylase")to` Maltose + Isomaltose + Limit dextrins
In small intestine
(i) Pancreatic juice contains pancreatic amylase , which acts in further breakdown the starch.
Starch and glycogen `overset("Pancreatic")underset("Amylase")to` Maltose + Isomaltose + Limit dextrins
(ii) Intestinal juice contains the following
Intestinal amylase hydrolyses the remaining starch and glycogen.
Maltose `overset("Maltase")to` Glucose
Isomaltose `overset("Isomaltase")to` Glucose
Sucrose `overset("Sucrase")to` Glucose + Fructose
Lactose `overset("Lactase")to` Glucose + Galactose
Digestion of Proteins starts
In stomach Inactive from of pepsin is secreted known as pepsinogen which on presence of HCl forms pepsin and digests protein,
Pepsinogen + HCl `to` Pepsin
Proteins " " `overset("Pepsin")to` Proteoses and peptones
In small intestine
(i) Pancreatic juice secretes Trypsinogen, chymotripsinogen (inactive from of trypsin which an activation forms trypsin and digest protein.

(ii) Intestinal juice
" "Pepptides `overset("Aminopeptidases")to` Dipeptides + Amino acids
Dipeptides `overset("Dipeptidases")to` Amino acids
Digestion of Fats begins
In small intestine
(i) Bile emulsifies fats into smaller droplets
(ii) Pancreatic juice present in small intestine acts as follows
" " Treglyceride `overset("Lipase")to` Fatty acid + lipase
" " Fatty acid + Glycerol `overset("Lipase")to` Monoglycerides diglyceride
(iii) Intestinal juice acts as
Triglycerides + Diglycerides `overset("Intestinal")underset("Lipase")to` Fatty acids and glycerol + Monoglycerides