Science KS3

• The lungs are basically two sacks of air.
• The windpipe is also known as the trachea.
• Diagram of the lungs:
• ........................ | Trachea
  
• ........................ |
  
• ...................( o / \ o ) Bronchus
• ................(... \ /.. \ /...) Bronchioles
  
• ...............(......o- -o......)
  
• ..............(........./ \..........)
  
• .............(....... o...o..........)
• o represent alveoli
• ( or ) represent intercostal muscles
• Ignore the full stops
  

We breath in:

• 78% Nitrogen (N2)
• 21% Oxygen (O2)
• 0.04% Carbon Dioxide (CO2)
• 0.02% Water Vapour (H2O)
• 0.94% Noble Gases

We breath out:

• 78% Nitrogen
• 17% Oxygen
• 3.06% Carbon Dioxide
• 1% Water Vapour
• 0.94 Noble Gases

• Diffusion: particles move from an area of high concentration to an area of lower concentration until they are spread ouy.
• Flowchart of the respiratory system:

Nose or mouth -> trachea -> bronchi -> bronchioles -> alveoli -> Heart

• Gas exchange flowchart:

Oxygen in alveoli -> Capillary

Carbon Dioxide in capillary -> Alveoli

• Spongy formation = more surface area. Means gas exchange happens quicker.
• Red blood cells carry oxygen from the capillary to the heart to the muscles.

• Element - Made up of the same atoms that cannot be broken down into anything simpler
• Compound - Two or more elements bonded.
• Mixture - Different atoms mixed together

• Solid to liquid is melting
• Liquid to gas is evaporation
• Gas to solid is desublimation
• Liquid to solid is freezing
• Gas to liquid is condensation
• Solid to gas is sublimation

• A push, pull or twist that acts on an object.
• They can change the speed of an object, the direction of the object or the shape of an object.
• We measure them in newtons.
• Gravity pulls objects downwards.
• Air resistance (or drag) acts against anything moving through air.
• Friction acts against anything moving.
• Upthrust acts upwards on objects that are afloat.

Equation triangle:

Distance

Speed | Time

Speed of a bat: distance divided by time.

Distance of car: speed times time

Time of the run: distance divided by speed.

• Nucleus contains genetic information
• Cell wall keeps the shape of the cell
• Membrane allows certain things to get in or out
• Vacuole stores things for the plant.
• Chloroplasts photosyntesis.
  • Photosynthesis: the process by which plants make food for themselves.
• Cytoplasm prevents the cell from collapsing.

A root hair cell has all these things except for the chloroplasts. They have a root "hair" that absorbs nutrients from the ground.

Chloroplasts contain chlorophyll. This gives the leaf a green colour. Here photosynthesis takes place.

Photosynthesis equation:

Carbon dioxide + water -----------------------> glucose + oxygen

..........................................light

......................................chlorophyll

Stoma are holes in the bottom of the plant. They let gases in and out of the plant.

Plants make glucose as their food. It is necessary to "feed" the plant.

Some plants do not need all this glucose. It gets stored as starch.