Science grade V

• Digestion


  The process of breaking down food into smaller parts so the body can use them for energy, growth, and cell repair
• Digestion is important because your body needs nutrients from food and drink to work properly and stay healthy
• Nutrients


  • Proteins
  • Fats
  • Carbohydrates
  • Vitamins
  • Minerals
  • Water
• Digestion process


  1. Proteins are converted into amino acids

  2. Carbohydrates are converted into simple sugars

  3. Fats are broken down into fatty acids and glycerol
• Digestive system


  Our digestive system breaks food down into simpler substances
• Parts of the digestive system

  • Mouth
  • Gullet/Esophagus
  • Stomach
  • Pancreas
  • Liver
  • Gallbladder
  • Small intestine
  • Large intestine (colon)
  • Rectum
  • Anus
• Mouth


  • Teeth chew and grind food into smaller pieces
  • Saliva helps digest food slightly and makes it soft enough to swallow
• Gullet/Esophagus


  • Transports food from mouth to stomach by peristalsis
• Stomach


  • Digests food with enzymes
• Pancreas


  • Makes digestive juice with enzymes that break down carbohydrates, fats, and proteins
  • Delivers digestive juice to small intestine
• Liver


  • Makes digestive juice called bile that helps digest fats and some vitamins
  • Bile ducts carry bile from liver to gallbladder or small intestine
• Gallbladder


  • Stores bile between meals
  • Squeezes bile through bile ducts into small intestine when you eat
• Small intestine


  • Completes food digestion
• Large intestine (colon)


  • Removes water from undigested food
• Rectum


  • Connects the colon to the anus
• Anus


  • Passes waste out of the body
• The motion of digestive organs is important
• To keep our digestive system healthy

  • Eat more fruits & vegetables
  • Drink more water to aid digestion
  • Chew food properly
  • Store uncooked or uneaten food in refrigerator
• When handling and eating food, we must

  • Keep our hands clean
  • Cover food that is left on the table
  • Not consume expired food
  • Wash fruits and vegetables thoroughly
  • Clean and cook food properly
  • Only eat at places that are clean
• Invertebrates


  Animals without a backbone
• Types of invertebrates with jointed legs

  • Insects
  • Millipedes
  • Spiders
  • Crustaceans
• Types of invertebrates without jointed legs

  • Starfish, sea urchins, and sea cucumbers
  • Jellyfish, corals, and sea anemones
  • Sponges
  • Snails, slugs, clams, and mussels
  • Worms
• Invertebrates


  • With jointed legs
  • With no jointed legs
• Starfish, sea urchins, and sea cucumbers are invertebrates with no jointed legs
• Jellyfish, corals, and sea anemones are invertebrates with no jointed legs
• Sponges are invertebrates with no jointed legs
• Snails, slugs, clams, and mussels are invertebrates with no jointed legs
• Worms are invertebrates with no jointed legs
• Insects, millipedes, spiders, and crustaceans are invertebrates with jointed legs
• Change of state


  A substance changes its state when it gains heat or loses heat
• Changes of state


  • Colour, shape, volume, and texture can change during a change of state
• Melting of butter


  1. Butter gains heat and melts to form liquid butter

  2. Liquid butter has the properties of a liquid

  3. Butter's shape, volume, and texture change
• Hardening of wax


  1. Hot liquid wax loses heat to the surroundings and hardens to form solid wax

  2. Wax's shape, volume, and texture change
• Drying of water puddles

  1. Water in a puddle gains heat from the surroundings and slowly changes into water vapour

  2. Water's shape, volume, and texture change
• Changes of state in water when water gains heat

  • Solid state to liquid state (melting)
  • Liquid state to gaseous state (boiling)
  • Liquid state to gaseous state (evaporation)
• Changes of state in water when water loses heat

  • Liquid state to solid state (freezing)
  • Gaseous state to liquid state (condensation)
• Refraction of light


  Light travels in straight lines, however, when light travels from one medium to another, it bends. The bending of light at the boundary of the two media is known as refraction.
• Refraction occurs because the speed of light changes as it enters a different medium.
• How a lens works

  Light bends when it passes through a lens. A lens is a carefully moulded piece of transparent material, such as glass or plastic, which refracts light to form an image.
• Lenses


  • They are used to magnify or reduce the size of the images of objects
  • They are used in magnifying glasses, microscopes, spectacles, cameras, and telescopes