An introduction to Plants Plant Nutrition

Recap: Plant Cell Cytoplasm Chloroplast Cell Wall Nucleus Cell Membrane Vacuole made up of cellulose Structural support for the cell Single, large vacuole cell sap contains water and dissolved substances Keeps cell firm by taking in water small disc-like structures found in plant cells contains chlorophyll for photosynthesis Jelly-like substance that fills the cell Site of chemical reaction Thin, partially permeable layer Controls movement of substances entering and leaving the cell Spherical in shape Controls cell activities Contains DNA in chromosomes Mitochondria Generates energy

Shocked Russian surgeons open up man who thought hehad a tumour... to find a FIR TREE inside his lung

The tree, measuring 5cm, was discovered by Russian doctors when they opened up Artyom Sidorkin, 28, to remove what they thought was a tumour. Medical staff believe that Mr Sidorkin somehow inhaled a seed, which later sprouted into a small fir tree inside his lung. The patient had complained of extreme pain in his chest and had been coughing up blood. Doctors were convinced he had cancer.

Photosynthesis photos = light, synthesis = putting together or manufacturing The process whereby plants made use of light energy to manufacture food. Type of nutrition: Autotrophic Nutrition (building up of complex organic molecules from simple molecules)

Young willow tree: 2.25kg Soil: 90kg Trunks, roots, branches: 76.1kg Soil: 88kg Jan Baptista van Helmont By how much did the mass of the willow tree increased? By how much did the mass of the soil decrease? So, do you think plants get their food from the soil? If not, where?

Photosynthesis glucose + oxygen + water Light energy + 12 H2O + 6 CO2 C6H12O6 + 6 O2 + 6 H2O

Conditions essential for photosynthesis Sunlight To provide energy to split the water molecule Carbon dioxide To provide a source for the manufacturing of carbohydrate during photosynthesis

Conditions essential for photosynthesis III. Chlorophyll Pigment in plants that absorbs sunlight IV. A suitable temperature Photosynthesis is dependent on: Enzymatic reactions in the chloroplasts So think about what happens in low temperature and at extreme high temperature.

Limiting Factors Definition: Any factor that directly affects a process if its quantity is changed. The rate of photosynthesis is affected by: Light intensity The concentration of carbon dioxide Temperature

Light Intensity Rate of photosynthesis Light intensity 0 Initially as light intensity increase from 0 to point A, the rate of photosynthesis also increases. Beyond point A, further increase in light intensity does not increase rate of photosynthesis. Therefore, light intensity is no longer the limiting factor Therefore, light intensity is the limiting factor Therefore, temperature or carbon dioxide concentration becomes the limiting factor.

Carbon dioxide Concentration Rate of photosynthesis Light intensity 0 When temperature remains constant, and carbon dioxide concentration is increased (0.13%), rate of photosynthesis increases Therefore, carbon dioxide is the limiting factor in AB in graph 1

Temperature Rate of photosynthesis Light intensity 0 Photosynthesis is dependent on enzymatic reactions in the chloroplasts. So increase in temperature  increase KE of the substrate and enzyme molecules  Increase molecular movement of the molecules  increase effective collision between the substrate and enzyme  increase formation of enzyme-substrate complex  increase rate of reaction Increasing temperature from 20oC to 30oC cause a large increase in the rate of photosynthesis as shown in graph 4 Therefore at point EF, temperature is the limiting factor.