The Alimentary Canal

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The Alimentary Canal

• Standard Grade Biology

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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
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Can you name the 2 different ways we breakdown
food in our bodies?

• Mechanical Digestion
• -teeth
• Chemical Digestion
• -enzymes
• -bile
• -stomach acid

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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

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

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3. Peristalsis

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

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Digestive Enzymes

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

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Digestion

• the breakdown of large insoluble molecules into
  soluble molecules

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

• SALIVA
• Salivary amylase

• GASTRIC JUICE
• Hydrochloric acid
• Pepsin (protease)

Bile

• PANCREATIC JUICE
• Pancreatic lipase

INTESTINAL JUICE
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In the Mouth

• Starch maltose
• Broken down into glucose later by other amylases

Salivary amylase
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In the stomach

• Protein peptides
• Broken down into amino acids later by other
  proteases

pepsin
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In the pancreas.

• Fats fatty acids and glycerol

Pancreatic lipase
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After all the digestive enzymes have done their
work

• Glucose
• Amino acids
• Fatty acids
• Glycerol

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Finish the sentence.

• Something new I learnt today was..
• Something I found difficult to understand was
• The thing I need to revise from todays lesson
  is

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