photosynthesis
DESCRIPTION
Photosynthesis. Photosynthesis. Photosynthesis. The process where light energy is converted into chemical energy. Photosynthesis. Autotrophs change light energy into chemical energy in the process of photosynthesis. - PowerPoint PPT PresentationTRANSCRIPT
Photosynthesis• Autotrophs change light
energy into chemical energy in the process of photosynthesis.
• Plants use light energy to convert water and carbon dioxide into oxygen and carbohydrates (sugars and starches)
Process of Photosynthesis• Photosynthesis is a
process used by green plants
• The is a type of autotrophic nutrition.
• Photosynthesis is carried out by chloroplasts, which contain chlorophyll
• In the chloroplasts, CO2 and H2O are used to form C6H12O6 and O2
Process of PhotosynthesisLABEL the reactants & products
below
6 CO2 + 6 H2O C6H12O6 + 6 O2
= light energy trapped in the chloroplast makes this process happen
Photosynthesis Equation
6CO2 + 6H2O C6H12O6 + 6O2
carbon water light energy sugar oxygen
dioxide (glucose)
Photosynthesis Equation
• Requirements:– 6CO2 – carbon dioxide
is absorbed from the environment
– 6H2O – water absorbed from the environment
– Energy – energy from the sun is trapped by the chlorophyll in the chloroplasts
• Products/Wastes:– C6H12O6 – organic sugar
(glucose) is stored in the plant
– 6O2 – oxygen is released as a waste product
6CO2 + 6H2O C6H12O6 + 6O2
carbon water light energy sugar oxygen
dioxide (glucose)
or water
Factors Affecting Photosynthesis
• Water or Carbon dioxide (wax prevent water loss)
• Temperature (0-35°C for enzymes)• Light intensity (min and max)
Light and Pigments
• Energy from the sun travels to Earth in the form of light of different wavelengths of the visible spectrum as different colors
• Plants gather the sun’s energy with light-absorbing molecules called pigments.
Chloroplasts• Chlorophyll in the chloroplast is
the green pigment that captures light energy to carry out photosynthesis.
• Oxygen is released through the leaves
• Organic sugars made are used by the autotroph to grow/develop or stored as carbohydrates or lipids.
Inside Chloroplasts• Photosynthesis takes place
inside chloroplasts
• Thylakoids = saclike photosynthetic membranes containing chlorophyll and other pigments
• Grana = stacks of thylakoids
• Stroma = region (space) outside thylakoids
Light vs. Dark Reactions• Light-dependent
reactions take place within the thylakoid membranes.
• Light-independent reactions, or the Calvin cycle, take place in the stroma.
NADPH• High-energy electrons are transported
from the chlorophyll by carrier molecules• NADP+ is one carrier molecule that carries
two high-energy electrons with a hydrogen ion (H+) converting it into NADPH
• The NADPH carries the electrons produced by light absorption in chlorophyll to chemical reactions throughout the cell.
Light-dependent Reactions
• Require LIGHT!• Use energy from
light to produce oxygen and convert ADP & NADP+ into the energy carriers ATP & NADPH