The Digestive System Flashcards
What is the structure of the stomach?
It is continuous with the oesophagus and the duodenum, it is below the diaphragm, has muscular walls and gastric pits to secrete HCl and protease.
What is the function of the stomach?
The muscular walls chum up the food (mechanical) and the HCl kills bacteria. The pH2 is for protease to digest protein.
What is the structure of the pancreas?
It is leaf shaped, below the stomach, the pancreatic duct leading to the duodenum. Contains lobes aka the Islets of Langerhans. 1
What is the function of the pancreas?
Exocrine glands for endopeptidase, pancreatic lipase and amylase into the duodenum via duct. The endocrine glands contain insulin and glucagon. It regulated blood glucose levels.
What is the structure of the gallbladder?
Underneath the liver with a bile duct leading to the pancreatic duct.
What is the function of the duodenum?
Connects the stomach to the small intestine, site of neutralisation, site of action for endopeptidase, pancreatic amylase and lipase secreted from the pancreas.
What is the structure of the duodenum?
25cm of small intestine, curves from stomach around the pancreas. Secretes from the gallbladder and pancreas are added via the pancreatic duct.
What is the function of the gallbladder?
Stores bile produced by the liver and releases via a bile duct to pancreatic duct to the duodenum. The bile at pH8 neutralises (stomach acids) HCl
What is the function of ileum?
The microvilli is the site of absorption to the blood stream. Or the lymphatic system into lipids.
What is the structure of the ileum?
Majority of the small intestine, highly folded into villi with vast blood supply. The villi is covered by epithelial cells with many microvilli to increase surface area.
In the duodenum, … … continues to hydrolyse the … … in starch to maltose.
- pancreatic amylase
- glycosidic bonds
What is the function of the colon?
Water absorption, and pushes paeces along to the rectum. Beneficial bacteria produce vitamins and folic acid?
In the mouth the enzyme … … starts to … (break bond by inserting water) … to …
- salivary amylase
- hydrolyse
- starch
- maltose
What is the structure of the colon?
Lower right side of the body, up,across,down left side surrounded by small intestine, has very muscular walls.
Maltose is then hydrolysed to glucose by … enzymes embedded in the membrane of the epithelial cells lining the …
- maltose
- ileum
Where is amylase produced?
salivary glands
pancreas
What reaction is caused by amylase?
starch hydrolysed to maltose
Where is maltase produced?
embedded in the epithelial cell membrane of the ileum
What reaction is caused by maltase?
maltose hydrolysed to glucose
How is glucose absorbed?
facilitated diffusion and active transport using specific carrier proteins.
What mechanism is responsible for glucose absorption?
contransport
Proteins are hydrolysed by enzymes called … This process begin in the … Pepsin, an … with an optimum pH of 2 hydrolyses the … bonds within a … chain. This produces many smaller … chains.
- protease
- stomach
- endopeptidase
- peptide
- polypeptide
- polypeptide
Why does pepsin not denature in the stomach?
As pepsin has an acidic optimum pH
What has a pH of 8 in the duodenum?
pancreatic juices
bile
trypsin
What does the exopeptidase do in the pancreatic juices?
hydrolyses the peptide bonds at the end of the protein.
What happens if dipeptides are produced?
dipeptidases is embedded in the cell surface membrane of the epithelial cells of the ileum hydrolyse these into amino acids.
Where is trypsin and exopeptidase found?
pancreas with a pH of 8, functions in duodenum
What reaction is cause by trypsin and pepsin?
polypeptides turn into shorter ones
Where is pepsin produced?
stomach with a pH of 2
What reaction is caused by exopeptidase?
shorter polypeptides to amino acids.
Where is dipeptidase produced?
embedded in the epithelial cell membrane of the ileum.
Where are lipids only digested?
within the lumen of the small intestine
What reaction is caused by dipeptidase?
dipeptides to amino acids.
Where is bile produced and stored?
produced in the liver and stored in the gallbladder.
How does bile get released into duodenum?
via the bile duct and the pancreatic duct
What is the emulsification of fat droplets?
break up the lipid base with water base, the enzymes work quicker.
What are some advantages of emulsifying the lipids?
- increased surface area
- lipids break down faster from enzymes.
