chemical digestion Flashcards
what is chemical digestion?
Chemical digestion is the breakdown of
large insoluble molecules into small
soluble molecules.
role of chemical digestion
The role of chemical digestion is to produce
small soluble molecules that can be
absorbed
mention the three enzymes
amylase, protease, lipase
what does amylase break down and to what
breaks down starch to simpler sugars
what does protease break down and to what
breaks down protein to amino acids
what does lipase break down and to what
breaks down fats to fatty acids and glycerol
where is amylase secreted?
pancreas and salivary glands
where is amylase’s site of action
mouth and duodenum
what is the special conditions for amylase
slightly alkaline
what is the substrate digested in amylase
starch
what is the end products for amylase
maltose and glucose
where is protease (pepsin) secreted
stomach
where is protease (pepsin) site of action
stomach
where is protease (trypsin) secreted
pancreas
where is protease (trypsin) site of action
small intestine
what is the special conditions for protease
acid in stomach, alkaline in duodenum (small intestine)
what is the substrate digested in protease
protein
what is the end products for protease
amino acids
where is lipase secreted
pancreas
where is lipase’s site of action
duodenum
what is the special conditions for lipase
alkaline
what is the substrate digested in lipase
Fat
what is the end products for lipase
Fatty acids and glycerol
starch is broken down to what
amylase
where is amylase found
saliva, pancreas, small intestine
amylase breaks starch into what
maltose
from maltose to what
glucose
proteins bare broken down by
protease
pepsin and trypsin are found where
pepsin in stomach and trypsin in small intestine
fats are made up of
fatty acids and glycerol
fats are broken down by what
lipase
lipase is found where
small intestine and pancreatic juice
glycogen is stored where
liver
glucose is converted to what
glycogen
the stomach secretes what kind of juice
gastric juice
the pancreas secretes what kind of juice
pancreatic juice
the mouth has what
salivary glands
gastric juice contains what
hydrochloric acid and pepsin, also it is acidic
pancreatic juice contains
amylase, protease, lipase. it also works in the small intestine.
the salivary glands produce what
saliva and amylase and they are alkaline
functions of hydrochloric acid
- kills bacteria in food and gives an acid PH for enzymes
- denaturing enzymes in harmful microorganisms in food
- giving the optimum Ph for pepsin activity
explain digestion of starch
amylase breaks down starch to maltose in the mouth.
maltase breaks down maltose to glucose on the membranes of the epithelium lining the small intestine.
mouth–starch—maltose—-small intestine
maltose is broken down by maltase to form glucose
explain digestion of protein
pepsin breaks down protein in the acidic conditions of the stomach.
trypsin breaks down protein in the alkaline conditions of the small intestine.
protein is broken down by pepsin to form polypeptide and polypeptide is broken down by trypsin to form amino acids
where does protein digestion take place
stomach and duodenum
what is bile
Bile is an alkaline mixture that neutralises the acidic mixture of food and gastric juices entering the duodenum from the stomach, to provide a suitable pH for enzyme action.
Emulsifies fats to increase the surface area for the chemical digestion of fat to fatty acids and glycerol by lipase.
where is bile released
the small intestine
where is bile made+ stored + transferred
bile is made in the liver, stored in the gall bladder and transferred to the duodenum by the bile duct
the function of the hydrogen carbonate in bile
neutralising the acid mixture of food and gastric juices as it enters the duodenum, this is important because enzymes secreted into the duodenum need alkaline conditions to work at their optimum rate
how is a low ph helpful in the stomach
- low ph kills bacteria in food that we have ingested as it denatures the enzymes in their cells, meaning they can’t carry out any cell reactions to maintain life
- pepsin, produced in the stomach, an example of an enzyme that has a very low optimum ph- around ph 2
- hydrochloric acid produced in the stomach remains within the optimum range for pepsin to work at its fastest rate
more water is absorbed where
small intestine and large intestine
large intestine is made of
anus, colon, rectum
