Transcript Photosynthesis Notes

Photosynthesis Notes
Biology Unit 05 Lesson 01
Chemosynthesis
 Chemosynthesis uses energy released from
chemical reactions to produce food for
organisms.
 Organisms that carry out chemosynthesis
are microbes (bacteria) that live far from
the Sun, such as deep on the ocean floor.
Which Organisms Carry Out
Photosynthesis?
 Autotrophs such as plants and some
protists
Photosynthesis
 Photosynthesis is the cellular process in
which autotrophs capture light
energy and convert it to chemical
energy (glucose) using carbon
dioxide and water.
Equation for Photosynthesis
 6CO2 + 6H2O + Light Energy  C6H12O6 + 6O2
 Carbon Dioxide + Water + Light Energy 
Glucose (sugar) + Oxygen
Reactants & Products
of Photosynthesis
REACTANTS
PRODUCTS
Carbon Dioxide
Glucose (sugar)
Water
Oxygen
Light Energy
Where Does Photosynthesis
Occur?
 Chloroplasts
 Contain chlorophyll in plant cells or autotrophs
Types of Chlorophyll
Chlorophyll a absorbs indigos,
blues, oranges and little red.
Chlorophyll b absorbs a higher
rate of blue and yellows and little
orange.
Both reflect green wavelengths
Light Dependent Reaction
 Occurs in the thylakoid
 Water is absorbed through roots.
 Sunlight enters the chloroplast, causing H2O
molecules to split.
 O2 leaves as a waste product through the
stomata.
 NADP+ picks up the H+ ions (becoming NADPH)
and moves them to the stroma for the light
independent reaction (Calvin cycle).
Stomata
 Found on the under side of the leaf.
 Surrounded by guard cells that open and close
to allow for CO2, H2O and O2 exchange
 Close during the hottest parts of the day to
prevent transpiration, evaporation from plants
Light Independent Reaction –
Calvin Cycle
 Carbon dioxide from the atmosphere enters
 H+ breaks off from NADPH
 NADP+ returns to the Light Dependent
Reaction
 Carbon dioxide becomes “fixed” with the H+
producing the glucose molecule C6H12O6.
Reactants & Products
of Photosynthesis
REACTIONS
PRODUCTS