Digestion And Absorption Flashcards
Where are the villi
Situated at the interface between the lumen of the intestines
Name 4 ways in which villi increase the efficiency of absorption
Increase surface area
Thin walls
Move to maintain concentration gradient
Rich supply of blood vessels vessels
Why is it good that the villi contain muscles
They regularly contract and relax which mixes the contents of the small intestine
This ensures that as glucose is absorbed new glucose is coming in
Where are the microvilli found
Epithelial cell’s
Define digestion
The process in which large molecules are hydrolysed by enzymes into small molecules which can be absorbed and assimilated
What are the two stages of digestion
Mechanical
Chemical
Explain mechanical digestion
Teeth break down food, increasing SA
Stomach further breaks food down during peristalsis
Explain chemical digestion with saliva
Enters and adds salivary amylase you hydrolyse starch to maltose and maintains ph through minerals
Explain chemical digestion through stomach
HCl creates acidic conditions, protease in gastric juices hydrolyse proteins and amylase is denatured
Explain chemical digestion in the small intestine
Pancreatic juice is added for more hydrolysis of starch
Epithelial cells produce maltase to produces alpha glucose
Fats digested
What do carbohydrases break down
Hydrolysed carbs to monosaccharides
What does lipase break down
Lipids into glycerol and fatty acids
What do proteases break down
Proteins into amino acids
What do glucose polymers break down into
Disaccharides
What do disaccharides break down into
Maltose sucrose lactose lacrosse
What is maltose broken down into
2 glucose
What is sucrose broken down into
1 glucose and 1 fructose
What is lactose broken down into
1 glucose and 1 galactose
How is starch digested into the body
Amylase in saliva hydrolysed alternate glycosidic bonds of starch to produce di maltose
Pancreatic juice contains amylase
Maltase in ileum hydrolyses maltose to alpha glucose
Where is sucrose broken down
In SI and epithelium cell lining as they release sucrase
What is a micelle
A sphere of triglycerides
Why can we be lactose intolerance
After childhood our production of lactase reduces and for some it reduces to non
Where are lipases produced
Pancreas
What does lipase hydrolyse
The Ester bond to form fatty acids and monoglyceride
