8.1 Overview of Photosynthesis
• Photosynthesis converts solar energy into
chemical energy.
• Organisms that carry on photosynthesis are
called autotrophs.
• Heterotrophs are organisms that feed on other
organisms.
• Autotrophs and heterotrophs use organic
molecules produced by photosynthesis
• Pigments allow photosynthetic organisms to
capture solar energy.
8.1 Overview of Photosynthesis
• Flowering Plants as Photosynthesizers
– Photosynthesis occurs in the green parts of plants
– Leaves contain mesophyll tissue specialized for
photosynthesis
– Water is taken up by roots and transported to leaves
by veins
– Carbon dioxide enters through openings in the
leaves called stomata
– Light energy is absorbed by chlorophyll and other
pigments in thylakoids of chloroplasts
Leaves and Photosynthesis
8.1 Overview of Photosynthesis
• Photosynthetic Reaction
– Solar energy + 6CO2 + 6H2O  C6H12O6 + 6O2
• Glucose and oxygen are the products of
photosynthesis
• The oxygen given off comes from water
• CO2 gains hydrogen atoms and becomes a
carbohydrate
8.1 Overview of Photosynthesis
• Photosynthesis consists of two sets of reactions
– Photo refers to capturing light
– Synthesis refers to producing a carbohydrate
• The two sets of reactions are called the:
– Light Reactions
– Calvin Cycle Reactions
8.5 Photosynthesis Versus
Cellular Respiration
• Both plant and animal cells carry out cell
respiration
• Only plant cells photosynthesize
• Both processes utilize an electron transport
chain and chemiosmosis for ATP production
• Photosynthesis reduces CO2 to carbohydrates
and releases O2
• Respiration utilizes O2 and gives off CO2
Photosynthesis and Respiration
Compared