Chpt 5 The Digestive System And Enzymes Flashcards
What is digestion?
Its the breakdown of large, insoluble food molecules into small, soluble food molecules.
What are the two types of digestion?
Physical and chemical digestion
Explain physical digestion
Where food is broken down by teeth and the churning action of the muscles in the digestive system.
Explain chemical digestion
Where food is broken down by enzymes
What are enzymes and what are their functions?
Biological catalysts and they speed up the chemical reactions in cells.
What is a catalyst?
A chemical used to change the speed of a reaction without being used up in the reaction
What is an example of an enzyme?
Amylase
Where is amylase found?
In saliva in the mouth and small intestine
What does amylase do?
Breaks starch down into maltose
What is the substrate?
The substance on which an enzyme works on
What is the product?
The substance formed as a result of the reaction
What is the chemical formula for amylase acting on starch?
Starch + amylase -> maltose + amylase
Substrate) + (enzyme) -> (product) + (enzyme unchanged
Look at page 28 for experiment
On amylase
What are the stages in human nutrition (feeding)?
1) eating- food into mouth
2) digestion - food broken down into smaller, soluble food molecules
3) absorption - food taken into bloodstream and carried to cells where its used
4) getting rid of undigested wastes like faeces
List the parts of the digestive system from top to bottom?
- mouth (L)
- salivary gland (R)
- oesophagus (L)
- liver (L)
- stomach (R)
- pancreas (R)
- large intestine (L)
- small intestine (R)
- appendix (L)
- rectum (L)
- anus (MIDDLE)
Explain the mouth
Its where digestion begins.
- The amylase begins to break down the starch in food to maltose sugar
- the teeth break the food into smaller pieces
Explain the salivary gland
Produces saliva containing enzymes
Explain the oesophagus
Its a muscular tube that carries food from mouth to stomach by muscular action (peristalsis)
Explain the liver
Produces bile which helps digestion of fats. It sorts and stores some digested food
Explain the stomach
its a muscular bag that holds food for 3-4 hours.
- produces enzymes and other digestive juices that chemically digest food
- churns and mixed the food
- hydrochloric acid is produces and it it kills bacteria and other germs
Explain the large intestine
It takes water back into the bloodstream leaving solid waste
Explain the pancreas
Produces digestive enzymes
Explain the appendix
It has no function in humans
Explain the small intestine
It produces more juices containing enzymes that are added to help digest the food. Fully digested food is absorbed into the bloodstream. Leftover water and undigested food is pushed into the large intestine.
