1. Photosynthesis

2. Process uses the sun’s energy to make glucose
Photosynthesis
Process uses the sun’s energy to make glucose
Carried out in green plants and some bacteria
Purpose is to trap sun’s energy and store it in
glucose (food for the plant)
Photosynthesis occurs in the chloroplast
SUN
photons
6CO H2O  C6H12O O2
carbon dioxide + water  glucose + oxygen 2

3. 6CO2 + 12H2O  C6H12O6 + 6O2 carbon dioxide + water  glucose + oxygen3

4. Pores in a plant’s cuticle through which
Stomata (stoma)
Pores in a plant’s cuticle through which
water and gases are exchanged
between the plant and the
Oxygen
(O2)
Carbon Dioxide
(CO2) & Water
Guard Cell
Guard Cell

6. Organelle where photosynthesis
Chloroplast
Organelle where photosynthesis
takes place.
Stroma: gel filled space
Outer Membrane
Inner Membrane
Thylakoid: green disks
Granum: stack
of thylakoids
Inter
Membrane
Space 6

7. Thylakoid Grana make up the inner membrane Thylakoid Membrane Granum
Thylakoid Space
(Lumen)
Granum
Grana make up the inner membrane 7

8. Why are
plants
green?

9. Pigments Pigments are light-absorbing compounds.
Pigments appear colored because they
absorb light of certain wavelengths
and reflect that of others.
Chlorophyll a and b are the primary
pigments in green plants that absorbs
red and blue/violet light and reflects
green light.

10. Light and Dark
Reactions

11. Photosynthesis Steps 1. Light reaction (Light-dependent reaction)
Chlorophyll traps sunlight and makes
electrons and ATP to run the dark
reaction.
2. Dark reaction (Light-independent reaction)
Calvin Cycle uses ATP and electrons from
the light reaction and carbon dioxide from
the air to make glucose.

12. All organisms require energy for:
ATP
All organisms require energy for:
Active transport
Cell division
Movement
Production of proteins 17

13. NADPH
NADP+ is an electron acceptor
NADP e H+  NADPH + H+

14. LIGHT REACTION Requires light Pigments absorb photons of light and
excite electrons
Occurs in two
photosystems in the
thylakoid membranes
Photosystem: a unit
of several hundred
chlorophyll molecules
and associated
acceptor molecules

15. Light Reaction Summary
Input:
light energy
H2O
Output:
ATP
NADPH O2 20

16. Dark Reaction (Calvin Cycle) American scientist Melvin Calvin
Occurs in the stroma.
Uses ATP and NADPH from
light reactions.
Uses CO2 to produce
glucose (C6H12O6).
To produce 1 glucose: it
takes 6 turns of the cycle and
uses 18 ATP and 12 NADPH.

17. Input: Output: Dark Reactions Summary ATP NADPH CO2 ADP NADP+ H2O
Sugars (glucose) 22

18. Rate of Photosynthesis
The rate at which a plant can carry photosynthesis is affected
by its environment.
1. Temperature – enzymes
directly impacted
2. Light intensity – no light
= no photosynthesis
3. Water - required
4. [CO2]- Calvin (Dark) cycle
requirements

20. The End!