Digestive System Flashcards
Each enzyme has an active site which have conditions specific that help them to work at their __________
Optimum
An example of an __________ is amylase (found in the mouth)
Enzyme
What are enzymes and what do they do
They are catalysts which speed up reactions
If particles move faster then they are more likely to collide and therefore ________
React
What is a substrate
A molecule that is changes in a reaction
If you increase the temperature too much then the enzymes will become ____________ and therefore will not work
Denatured
Outside their optimum pH an enzyme can become _____________
Denatured
What is bile
A green liquid made up of bile salts
What is the lock and key theory
That the substrate can fit into the active site exactly like a key fitting into a lock because the enzymes are very specific
The rate of an enzyme controlled reaction is affected by factors such as: (3)
Temperature
pH
Enzyme concentration
Substrate concentration
Bile ___________ lipids/fats
Bile emulsifies fats
What does emulsify mean
Break things down from big to small
The pH of the small intestine is about ___
9 (8-9) alkaline
How is the structure of a villus adapted for the absorption of the products of digestion
1: Large surface area
2: Capillaries help it take useful substances to other parts of the body
3: Blood moves continually in the capillaries
4: This maintains concentration gradient
5: For diffusion
6: Lacteal absorbs fatty acids + glycerol
7: Villi is one cell thick
Bile is made by the _________
Stored in the _______ _________
Travel down the _______ ______
Made by the Liver
Stored in the Gall Bladder
Travel down the Bile Duct
Functions of hydrochloric acid:
Kills bacteria
The right pH for the protease enzyme to work
Pancreatic enzymes are made by the ___________
The pancreas
Salivary amylase in the mouth turns starch into __________
Starch —–> Maltose (smaller sugars)
Pepsin in the stomach turns protein into ________ _______
Protein —–> Amino acids
Maltase in the small intestine turns maltose into ___________
Maltose —–> Glucose
Lipase, a lipid enzyme, turns lipids into _________ ________ + _____________
Lipids —–> fatty acids + glycerol
Trypsin in the small intestine turns proteins into ________ _______
Protiens —–> Amino acids
Most food is absorbed in the _______ ___________
Small intestine
The ___________ is very acidic due to Hydrochloric acid
Stomach
Function of the oesophagus:
Muscular tube which connects the mouth and stomach
Food passes along the oesophagus to the stomach by ______________
Peristalsis
Functions of the stomach:
Muscles breaks down food
Produces protease enzymes
Produces Hydrochloric acid
The stomach churns and mixes food to produce a thick liquid called _________
Chyme
When the sphincter muscle opens, food passes from the stomach into the ________ ____________
Stomach —–> Small intestine
As the stomach is strongly acid, it has an optimum _____ of about 2
pH
Partly digested food is held back in the stomach by a ring of muscle at the stomach outlet, called a ___________ muscle
Sphincter
Bile and pancreatic juice are ____________ therefore they neutralise the acidic contents that have arrived from the stomach
Alkaline
Function of the pancreas:
Produces enzymes (protease, amylase, lipase) and releases them into the small intestine
Enzymes break down food until they are small enough to be absorbed in the last part of the small intestine, the __________
The ileum
__________ move food along the gut
Muscles
When the longitudinal muscles contract and the circular muscles relax, the gut is made ___________
Longer
The intestine contains 2 layers, the __________ muscle layer and the __________________
Circular
Longitudinal
What is peristalsis
Muscle contractions which push food without the need of gravity
Chemical breakdown is finished in the ______________
Duodenum (top of the small intestine)
When the circular layer contracts and the longitudinal muscles relax, the gut is made __________
Smaller
The process of taking food into the body is called _____________
Ingestion
What is digestion
The breakdown of food in the body by enzymes
Products of digestion are ___________ into the bloodstream
Absorbed into the bloodstream
Digestion by enzymes is known as ____________ digestion
Chemical digestion
The job of bile is to emulsify fats as well as to ________________ the stomach acids
Neutralise the stomach acids
Carbohydrase breaks down sugars into __________
Glucose
Trypsin breaks down proteins into _____________
Proteins —–> peptides
Pepsin breaks down peptides into __________ _________
Peptides —–> amino acids
The individual cells lining the villi have structures called _______________ which further increase surface area
Microvilli
The villi absorb ____________ and ____________ __________ through the blood capillaries
Glucose
Amino acids
_________ _______ and _____________ are absorbed into the lacteal which lives in the middle of the villi
Fatty acids and glycerol
Before waste is removed from the body, it is stored in the ___________
Rectum
Function of the large intestine:
Excess water is absorbed
Amylase turns starch into maltose.
In this equation what is the enzyme, what is the substrate and what is the product(s)
Enzyme = amylase Substrate = starch Product(s) = maltose
Function of the anus
Where faeces leave the body
What is the removal of undigested food/waste
Egestion
Name the 2 types of digestion
Mechanical digestion
Chemical digestion
Proteases turn proteins into ________ _______
Amino acids
5 main stages of digestion
Ingestion Digestion Absorption Assimilation Egestion
2 types of chemical digestion
Enzymes
Bile
2 types of mechanical digestion
Teeth
Stomach muscles
Functions of bile:
Neutralises for enzyme conditions
Emulsifies fats
Function of the gall bladder:
Stores bile
Function of the liver:
Produces bile
How is the mouth adapted for digestion
Salivary glands produce amylase
Teeth break down food
Name the first 5 stages of digestion in order:
Ingestion Digestion Absorption (Molecules moving into blood) Assimilation (Molecules moving into cells) Egestion
