Digestion And Enzymes Flashcards
The digestion system - the mouth what are the two types of digestion that takes place in the mouth?
Physical digestion and chemical digestion.
What is physical digestion
Physical digestion is the breakdown of food using mechanical methods.
🔵It occurs in the mouth when the teeth cut and chew the food into smaller pieces.This allows chemical digestion to work better.
Explain chemical digestion .
Chemical digestion is the breakdown of food using enzymes.
🔵An ENZYME is a chemical (protein) produced by the body which speeds up chemical reactions in the body without the enzyme being used up.
🔵Enzymes are similar to catalysts used in chemistry.Enzymes are made of protein while catalysts are not made of protein.
🔵 Salivary helps soften food.It also contains an enzyme called (salivary) AMYLASE.
🔵 Amylase digests starch,breaking it down to a simpler auger called maltose.
Explain teeth .
There are four types of teeth in the adult human jaw.The sequence of the teeth for front to back is:incisors, canines, premolars and molars.
🔵 Molars have sharp edges like a chisel.They are used to cut,slice and nibble the food.
🔵 Canines are long and pointed.They are used to grip and tear food.
🔵 Premolars are large, rounded teeth.They are used for chewing, crushing and grinding the food.
Explain the function of the oesophagus.
The oesophagus or food pipe is a muscular tube.It forces food down to the stomach using a wave of muscular action.This muscular action is simulated by fibre I our diet.
Explain the function of the stomach.
The stomach is a muscular bag which traps food for a few hours.Hydrochloric acid in the stomach kills bacteria and also softens food.If this acid gets into the oesophagus it causes a stinging sensation called heartburn.The stomach also churns and physically digests and mixes the food.
What is then function of the small intestine.
The small intestine produces many more enzymes which complete the breakdown of food.In the lower part of the small intestine the digested food passes into the bloodstream.The food is said to be absorbed from the small intestine.
Explain the physical function of the liver.
The liver is complex organ which carries out a range of functions.One of its functions is to produce a liquid called bile.Bile passes from the liver to the small intestine.Bile helps to digest fat in the small intestine.
What are s the function of the pancreas
The pancreas produces a large range of enzymes.These enzymes pass from the pancreas into the small intestine where they help digest the food.
What is the function of the large intestine.
The material entering the large intestine contains a lot of liquid.If all this liquid was a lowed to pass out of the digestive system, we would surfer from diarrhoea.The large intestine takes water back into the bloodstream.The semi-solid waste waste material left in the large intestine is called faeces.If too much water is taken back the waste becomes too solid a condition called constipation.Faeces are stored in the rectum and pass out of the intestine through the anus.The loss of undigested food is called egestion.
What is a product.
The PRODUCT is the substance produced as a result of the action of an enzyme.For example,in a the mouth the enzyme amylase acts on starch. The product of this reaction is maltose.Amylase only acts on starch.It does not digest other foods such as protein and fat.
What is a substrate
The substrate is the substance that an enzyme acts on.In the mouth the substrate is starch,the enzyme is amylase and the product of the reaction is maltose.
What are the stages of feeding
🔵Food is taken into the mouth.
🔵The food is broken down or digested.
🔵The dissolved particles of food are carried by the bloodstream to all the cells of the body.
🔵 The food is used by the body for different purposes.
🔵 The waste material not taken is released from the digestive system.
