Organisation A

• Cells

  Smallest unit of life
• Organ

  
  

  Group of tissues persorming similar functions
• Organ systems: Made up from several organs that work together to form and function organisms
• Digestion in gullet / oesohphagus: Muscular tube

  peristalis - wave of muscle contractions forcing food down to stomach
• Digestion in stomach: Sphinter allows food to enter and squeezes shut to stop food / fluid moving back up

  stomach muscles churn and mix food with acids and enzymes

  acidic environment needed for digestion
• Liver (digestion): Produces bile - helps digestion of fat - stored in gall bladder
• Digestion in small intestine: Digested food molecules are absorbed through intestine wall and into bloodstream to be carried around body

  inside wall of small intestine thin with large surface area (villi) - quick and efficient absorption
• Enzymes: A biological catalyst

  protein with unique and specific shape
• Carbohydrate digestion: E.g. cereal, potato

  enzyme : amylase

  Made in : small intestine , pancreas

  Product : glucose

  Reaction occurs in : mouth , small intestine
• Fats and oils digestion: E.g. margarine

  enzyme : lipase

  Made in : small intestine , pancreas

  Product : fatty acids , glycerol
• Digestion in mouth: Mechanical and chemical digestion

  mechanical - teeth increasing surface area

  enzyme in saliva - amylase - breaks down starch