Standard Grade Biology The Alimentary Canal Standard Grade Biology

Can you sort out the statements into True and False? Carbohydrates, proteins and fats are all made up of carbon, hydrogen, nitrogen and oxygen. Fats are made up of smaller units called amino acids Starch is a large carbohydrate molecule Proteins are made up of one or more glucose molecules Starch molecules can be broken down by amylase. Proteins are important for the growth and repair of cells

Can you name the 2 different ways we breakdown food in our bodies? Mechanical Digestion -teeth Chemical Digestion -enzymes -bile -stomach acid

1. Parts of The Alimentary Canal The alimentary canal (or gut) is the tube within the body through which food passes and is processed in various ways

mouth salivary glands oesophagus liver stomach pancreas large intestine small intestine anus

2. Role of the Mouth Teeth assist the mechanical breakdown of food Saliva is mixed with food during chewing Saliva contains the enzyme amylase which starts the digestion of food Salivary gland Saliva contains mucus that keeps the mouth moist and lubricates food for easier swallowing Salivary gland Salivary gland

3. Muscles of the Alimentary Canal Food has to be kept moving along the alimentary canal whilst being mixed with various juices These actions are brought about by muscles in the walls of the canal over which a person has little or no conscious control

3. Peristalsis The squeezing action of muscles that is used to move food along the alimentary canal http://www.lionden.com/peristalsis.htm

Digestive Enzymes What do the following enzymes breakdown? What do they break the large moleculs down into? Amlyases Lipases Proteases

Digestion ‘the breakdown of large insoluble molecules into soluble molecules’

Digestion and Digestive Juices Saliva GASTRIC JUICE Bile PANCREATIC JUICE INTESTINAL JUICE

Sites of production of main digestive juices Site of digestive juice production Main digestive juice produced Mouth Saliva Stomach Gastric juice Liver Bile (breaks down big fat droplets into little fat droplets Pancreas Pancreatic juice Small Intestine Intestinal juice

Digestion and Digestive Juices SALIVA Salivary amylase GASTRIC JUICE Hydrochloric acid Pepsin (protease) Bile PANCREATIC JUICE Pancreatic lipase INTESTINAL JUICE

In the Mouth… Starch maltose Broken down into glucose later by other amylases Salivary amylase

In the stomach Protein peptides Broken down into amino acids later by other proteases pepsin

In the pancreas…. Fats fatty acids and glycerol Pancreatic lipase

After all the digestive enzymes have done their work… Glucose Amino acids Fatty acids Glycerol

Finish the sentence…. Something new I learnt today was….. Something I found difficult to understand was… The thing I need to revise from today’s lesson is…

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