Photosynthesis

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Photosynthesis
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Overview

• Photosynthesis
• The process of capturing the energy of sunlight
  and changing it into chemical energy in the bonds
  of glucose.
• Plants take water(H2O) from the ground and carbon
  dioxide (CO2) from the air and convert sunlight
  energy into glucose (C6H12O6) and oxygen (O2)

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Photosynthetic Organisms

• Includes plants, algae, some protists and
  cyanobacteria

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Cyanobacteria

• blue-green algae
• Unicellular, grow in colonies large enough to see
• Evolved between 2.5 and 3.4 billion years ago,
  they were probably the first organisms to use
  sunlight in the production of organic compounds
  from water and CO2

Cyanobacteria and their relatives are responsible
for a major part of photosynthesis in oceans
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Leaf Structure

• What does it look like?
• Function of leaves

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Leaf functions

• Trap sunlight
• Perform photosynthesis
• Move food to storage areas in the plant
• Absorb CO2 from the air
• Minimize water loss from evaporation
• Leaf structure is related to function

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Parts of a leaf

• Cuticle water resistant coating on top of leaf
• Chloroplast contains chlorophyll
• Guard cells create the microscopic openings
  called stomata
• Stomata opening that regulate the exchange of
  CO2 and O2

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Why are leaves green?
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Because.

• Their cells are full of chloroplast!
• Chloroplasts contain chlorophyll (a pigment that
  reflects green lightwhich we see.so we see
  leaves as green)

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Chloroplast structure
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Summary of chloroplast structure

• Enclosed in a double membrane
• Grana a bunch of Thylakoid disks
• Thylakoid contains the pigments (chlorophyll)
• Stroma the liquid part of chloroplasts
  (containing electron transport system and loose
  enzymes)