Enzymes / Digestion Flashcards
Define an enzyme:
A substance which speeds up the rate of reaction, without being changed or used up in the reaction.
What macro-nutrient are enzymes made up of?
Proteins
Where on an enzyme does the substrate fit in?
The active site
What model can be used to replicate an enzymic reaction?
Lock and Key model
What does Amylase convert?
Starch into Maltose.
What does Maltase convert?
Maltose into Glucose.
What does Protease convert?
Proteins into Amino Acids
What does Lipase convert?
Lipids into Glycerol and fatty acids
Put simply, what are digestive enzymes function?
They break large, insoluble molecules into smaller, soluble ones.
How is Starch digested into Glucose?
Amylase converts; Starch -> Maltose.
Then Maltase converts; Maltose -> Glucose.
Where is bile produced and stored?
Produced in the liver and stored in the gall bladder.
Is bile an Acid or Alkaline?
Alkaline - It neutralises the HCl’s low pH.
What are the functions of bile?
Neutralise the pH - (actually make it Alkaline).
Emulsify fats - break them down into small globules (that have a larger surface area of fat for the enzyme lipase to work on.)
What process moves food through the gut?
Peristalsis
How does peristalsis work?
The muscular tissue in the alimentary canal compresses behind the food balls (Bolus), pushing them through.
What is the name for food balls that are moved through the alimentary canal is peristalsis?
Bolus
Which muscle is responsible for the contractions that squeeze food in the gut during peristalsis?
Circular muscles
Which (digestive) enzyme is produced in the saliva?
Amylase
Function of the mouth in the alimentary canal?
Teeth manually break down food.
Salivary glands produce saliva (containing amylase)
The amylase enzyme is present in the saliva of humans, what does this mean?
That starch is broken down into maltose before passing down the canal further.
Function of the gall bladder in the alimentary canal?
Stores bile
Function of the liver in the alimentary canal?
Produces bile
Function of the pancreas in the alimentary canal?
Produces digestive enzymes;
- protease
- amylase
- lipase
Where does pancreas release its digestive enzymes?
Small intestine
Function of the Oesophagus in the alimentary canal?
Muscular tube that connects food from the mouth to stomach.
Function of the stomach in the alimentary canal?
Pummels food with muscular walls.
Produces protease enzyme, pepsin.
Produces HCl
What is the function of HCl?
Kills bacteria
Optimum pH for pepsin to work (pH 2)
Function of the colon (large intestine) in the alimentary canal?
Absorption of excess water form foods
Function of the rectum (large intestine) in the alimentary canal?
Faeces is stored here
Function of the anus (large intestine) in the alimentary canal?
Where faeces leaves the body
Function of the duodenum (small intestine) in the alimentary canal?
Where food is mixed with digestive enzymes and bile
Function of the ilium (small intestine) in the alimentary canal?
Where digested foods nutrients are absorbed into the blood
