Cycles

• The Water Cycle

  A) Precipitation

  B) Transpiration

  C) Cooling

  D) Condesation

  E) Evaporation

  F) Percolation

  
• Evaporation


  Water turns from a liquid to a gas when it evaporates. Energy from the Sun can evaporate water from all places on the Earth’s surface such as puddles, ponds, lakes and oceans.
• Condensation


  After evaporation water can cool and convert from gas to liquid, often forming clouds.
• Transport


  Water within clouds can be blown many miles by strong winds and so transported to other areas.
• Precipitation


  Precipitation occurs when rain, snow, hail and sleet fall from the sky.
• Surface Runoff


  Much water will be absorbed into the ground after precipitation but if a large volume falls or the ground is already wet some water can run along the surface of the ground.
• Infiltration


  This occurs when water that has fallen as precipitation is absorbed into the ground. This can then be stored within underground rocks called aquifers.
• Transpiration


  Plants need to maintain a constant stream of water to their leaves for transport and support. So they allow some water to evaporate as water vapour from their leaves to mean that more is continually ‘pulled’ to their leaves from the soil.
• The Carbon Cycle

  A) Carbon dioxide

  B) Eaten

  C) decomposers

  D) Fossilisation

  E) Photosynthesis

  F) Combustion

  G) Respiration

  
• Photosynthesis is the only thing that removes carbon dioxide from the atmosphere.
• Carbon from dead plants and animals can end up as fossil fuels - when this is burned, it releases carbon.
• Some dead animals and plants can be eaten, be decomposed by microorganisms, or be turned into fuels by humans.
• Plants use carbon dioxide to make fats, proteins and carbohydrates through photosynthesis.
• Both plants and animals release carbon dioxide back into the atmosphere.
• The Carbon Cycle

  A) Respiration

  B) Decomposers

  C) Photosynthesis

  D) Combustion

  
• The Decay Cycle

  1. Plants decay
  2. Dead plants decompose in soil by decomposers
  3. The soil becomes rich in nutrients
  4. Rain and Sun causes plants to grow
• Nutrients and growth

  Mineral ions such as nitrates (plus magnesium ions and phosphates) are released so the plants can absorb them for protein synthesis for growth.
• Decay


  Materials from living things decay because they are digested/broken down by bacteria/fungi.
• Decomposition


  Microorganisms cause decay by releasing enzymes that break down compounds to be absorbed by their cells.

  E.g. Amylase is released to break starch down into glucose.

  Protease is released to break proteins down into amino acids.

  Lipase is released to break lipids down into fatty acids and glycerol.

  Absorption occurs by diffusion or active transport.
• Bacteria and fungi are the main groups of decomposers.

  They respire to produce carbon dioxide (which is released into the atmosphere for plants to take in for photosynthesis) and energy (which is used for other processes to occur like active transport).