plant nutrionts

• photosynthesis is the process by which green plants make carbohydrates from carbon dioxide and water, using energy from light
• carbon dioxide + water → glucose + oxygen
• apart from water and carbon dioxide, light and chlorophyll are needed for photosynthesis to take place
• chlorophyll is a green pigment present in the chloroplasts of plant cells
• light

  6CO2 + 6H2O ---> C6H12O6 + 6O2

  chlorophyll
• name the by-product of photosynthesis which sustains life

  oxygen
• name the structure through which carbon dioxide and oxygen move in and out of the leaf

  stomata
• glucose is used for:

  • energy source

  glucose is a source of chemical energy

  some of the glucose produced by photosynthesis is broken down during respiration to release energy
• glucose is used for:

  • storage

  glucose is converted into sucrose before being transpoted in the phloem (cuz sucrose is less reactive than glucose) to the different parts of the plant

  the sucrose can easily be changed back to glucose as and when needed by the plant

  
  

  plant also convert glucose to starch

  this is stored in granules in the chloroplasts and cytoplasm and acts as an energy store
• glucose is used for:

  • structural support

  some glucose is converted to cellulose

  it is an important component of the plant cell walls
• glucose is used for:

  • assisting pollination

  glucose is also used to make nectar

  nectar is a sweet, sugary liquid that attracts animals like insects and birds

  these animals in turn help with pollination
• the carbohydrate used to build the plant cell wal:

  cellulose
• T or F

  the oxygen released during photosynthesis helps to sustain like on earth T

  light energy is converted to chemical energy during photosynthesis T

  cellulose is produced during photosynthesis F

  the raw materials of photosynthesis are water and carbon dioxide T
• chlorophyll is present within the chloroplast of plant cells
• the green pigment that absorbs light energy from the sun is chlorophyll
• the name of the sugar that glucose is converted into for transport

  sucrose
• minerals are inorganic substances
• mineral ions are minerals that break down into their ions, which are charged particles formed when atoms, or groups of atoms, lose or gain electrons
• plants use magnesium ions for making chlorophyll
• there is a magnesium ion at the centre of each chlorophyll molecule, and this is vital for the correct function of chlorophyll
• plants use nitrate ions for making amino acids

  these substances are used by the plant to make the proteins is needs
• which mineral is most responsible for giving plants their green colour

  magnesium
• which ions are important for the synthesis of amino acids by plants

  nitrate ions
• which ions are important for the synthesis of amino acids by plants

  nitrate
• removing starch from the leaves ensures that any reserve stores of starch have been used up
• one way to destarch a plant is to place it in a dark room or dark cupboard for about 24 hours
• glucose made by photosynthesis is stored in the leaves as starch
• the presence of starch in the leaf is an indication that the plant has carried out photosynthesis
• testing for starch

  cautions and shit

  • wear eye protection
  • use forceps to move and place the leaf, avoiding direct contact with the boiling water and chemical solutions
  • make sure there are no flames nearby
  • take care with boiling water, which can cause scalding
  • take care with ethanol, which is highly flammable, harmful and health hazard
  • avoid breathing iodine vapour
• testing for starch

  equipment

  • a destarched leaf
  • forceps
  • beaker of boiling water
  • timer
  • test tube of alcohol solution
  • white tile
  • iodine solution
  • bunsen burner
• testing for starch

  equipment

  • a destarched leaf
  • forceps
  • beaker of boiling water
  • timer
  • test tube of alcohol solution
  • white tile
  • iodine solution
  • bunsen burner
• testing for starch

  running the experiment

  1. place a leaf in the beaker of boiling water for 30 seconds
  2. remove the leaf
  3. turn off the burner to make sure there is no flame present before you use the alcohol solution
  4. place the leaf in a test tube of alcohol solution until all of the green colour has been removed from the leaf
  5. remove the leaf from test tube and dip it into hot water to soften it and to remove excess alcohol
  6. place the leaf on a white tile and cover it with iodine solution
• testing for starch

  results

  the leaf will turn blue-black where starch is present
• testing for starch

  conclusion

  a blue-black colour indicates that the leaf contains a lot of starch

  this is an indication that the plant has carried out photosynthesis
• in photosynthesis investigations, why is a plant placed in a dark cupboard for 24 hours

  so that starch is removed from its leaves
• T or F

  plants can be destarched by placing them in bright light

  F
• the presence of starch is tested using iodine solution as an indicator
• role of chlrophyll during photosynthesis

  cautions

  • wear eye protection
  • use forceps to move and place the leaf, avoiding direct contact with the boiling water and chemical solutions
  • make sure there are no flames nearby
  • take care with boiling water, which can cause scalding
  • take care with ethanol, which is highly flammable, harmful and a health hazard
  • avoid breathing iodine vapour
• role of chlrophyll during photosynthesis

  equipment

  • plant with variegated leaves
  • forceps
  • beaker of boiling water
  • timer
  • test tube of alcohol solution
  • white tile
  • iodine solution
• role of chlrophyll during photosynthesis

  equipment

  • plant with variegated leaves
  • forceps
  • beaker of boiling water
  • timer
  • test tube of alcohol solution
  • white tile
  • iodine solution