9.2 Digestion Flashcards
TYPES OF DIGESTION
What is physical digestion?
The mechanical breakdown of food to form small particles
EG: chewing & peristalsis
TYPES OF DIGESTION
What is chemical digestion?
Decomposition proces of complex molecules to simple molecules
Involves enzymatic reaction
Digestion of carbohyrdrates in mouth
Presence of food in the mouth stimulates …?
Secretion of saliva
Digestion of carbohyrdrates in mouth
Function of salivary amylase
saliva contains salivary amylase, secreted by salivary gland
hydrolyses starch to maltose
Digestion of carbohydrates in mouth
what is peristalsis?
contraction & relaxation of muscles along the alimentary canal
pushes bolus through oesophagus till it enters stomach
Digestion of protein in the stomach
What epethelial cells are lined on the stomach wall?
function to form gastric glands
Chief cells, parietal cells, mucous cells
Digestion of protein in the stomach
Function of chief cell?
secrete pepsinogen (inactive pepsin)
activated by HCL to become pepsin
Digestion of protein in the stomach
Function of parietal cell?
secrete hydrochloric acid
Digestion of protein in the stomach
Function of mucous cell?
secrete mucus
Digestion of protein in the stomach
Function of pepsin
from chief cells, activated by HCL
hydrolyses protein into polypeptides
Digestion of protein in the stomach
3 functions of hydrochloric acid
from parietal cells
- create optimum pH for action of pepsin
- stop the activity of salivary amylase
- kill bacteria in food
Digestion of protein in the stomach
3 functions of hydrochloric acid
from parietal cells
- create optimum pH for action of pepsin
- stop the activity of salivary amylase
- kill bacteria in food
Digestion of protein in the stomach
function of mucus
from mucuous cells
protect stomach wall from reaction of HCL & digestive enzymes
Digestion of carbs, protein & lipids in the small intestine
function of pancreas
secretes pancreatic juice that contain …
TB pg 146
secretes pancreatic amylase, trypsin, lipase
Digestion of carbs, protein & lipids in the small intestine
function of liver & gallbladder
TB pg 146
- liver produces bile
- gallbladder stores bile
Digestion of carbs, protein & lipids in the small intestine
function of bile
TB pg 146
- prepare alkali condition for enzyme activity
- breaks down lipids into tiny droplets to increase surface area of lipids for lipase activity
Digestion of carbs, protein & lipids in the small intestine
Describe digestion of carbohydrates, protein & lipids in the duodenum
TB pg 146
- pancreatic amylase hydrolyses starch to maltose
- trypsin hydrolyses polypeptides into shorter peptides
- lipase hydrolyses lipids into fatty acids and glycerol
Digestion of carbs, protein & lipids in the small intestine
intestinal juice contains…
glands on ileum wall secrete mucus & intestinal juice
TB pg 147
maltase, sucrase, lactase, lipase, erepsin
Digestion of carbs, protein & lipids in the small intestine
summary of chemical digestion
TB pg 147
refer to workbook pg119
would be much clearer than this 😭
