Photosynthesis is the process by which plants convert carbon dioxide and water into glucose and oxygen using energy from sunlight. It requires the ingredients of water, carbon dioxide, light, and chlorophyll. Water is transported through the plant from the roots to the leaves, while carbon dioxide enters through pores in the leaves. Chlorophyll in the chloroplasts captures light energy to drive the reaction that produces glucose and oxygen. At night, plants respire like animals by absorbing oxygen and releasing carbon dioxide. Some plants are carnivorous and obtain nutrients by trapping and digesting animal prey using various trap types like pitfall, snap, flypaper, and suction traps.

1. Chapter 11
Photosynthesis

2. What is Photosynthesis?
• Definition:
– Photo  light
– Synthesis  putting together
• Photosynthesis is a process that converts
carbon dioxide and water into glucose and
oxygen using the energy from sunlight.

3. Ingredients of Photosynthesis
• Following are the ingredients
– Water
– Carbon Dioxide
– Light
– Chlorophyll

5. Water
• Water is taken in through the roots
of the plant
• Water is then transported to the
leaves by the tubes inside the plant
that carry water to the stems

6. Carbon Dioxide
• Carbon dioxide animals breathe out
from the air
• Plants absorb carbon dioxide from
the small pores on the leaves

7. • There are two sources of light
Light
– Natural light  Sun
– Artificial light  Light containing red
and blue rays
• Light is used to break down the
water in the plant into
– Hydrogen which combines with
carbon dioxide to create the food for
the plants and ultimately food for
animals as well
– Oxygen (a by-product) which the plant
gives off and animals use to breathe

8. • Incandescent light is not particularly
good for plants
– As it gives off too much heat at a close
proximity and often need to be placed too
far from the plant to do any real good.

9. Chlorophyll
• The process of photosynthesis
happens in the chloroplast, which
contain a green pigment called the
chlorophyll.
• Chlorophyll is the most important
ingredient of photosynthesis
– Because it captures the light from the
Sun and converts carbon dioxide and
water into glucose and oxygen.

10. • In short, Chlorophyll is the magic
compound that can grab that sunlight
and start the whole process

11. Respiration in Plants
• All living organisms need oxygen to live.
• Even though plants lack respiratory
system like animals, they need oxygen in
order to stay alive.
– They absorb oxygen from the air and expel
carbon dioxide

12. • During the day  Photosynthesis is the
dominant process in leaves
– Carbon dioxide is absorbed to make
glucose
• At night  Due to absence of sunlight,
photosynthesis does not occur. Instead,
the process of respiration occurs
– Oxygen is absorbed and carbon dioxide is
given off

13. No light
- Plants
produce CO2
Dim light
- Plants
produce both
O2 and CO2
Bright light
- Plants
produce O2

14. • All parts of the plant respire,
– Leaves, Stem, Roots and even the Flowers
• The roots of a plant also need oxygen
which they obtain from the air spaces in
the soil.
– If you give too much water to a plant in a
pot you could kill the roots by drowning
them!

15. Carnivorous Plants
• Carnivorous plants rely on animal prey for
sustenance.
• Have the most bizarre adaptations to lownutrient environments.
• Have features to attract, trap, kill, and digest
prey, and absorb nutrients.
–
–
–
–
Various invertebrates
Small frogs
Small fish
Small mammals

16. • Because insects are one of the most
common prey items for most
carnivorous plants, they are sometimes
called insectivorous plants.
• The most common habitat for these
plants is where nutrient concentrations
are low.

17. Traps work in a variety of ways.
• Pitfall traps of pitcher plants are leaves
folded into deep, slippery pools filled with
digestive enzymes.
•
Flypaper (or sticky or adhesive traps) of
sundews and butterworts are leaves
covered in stalked glands that exude
sticky mucilage.

18. • Snap traps (or steel traps) of the Venus
flytrap and waterwheel plant are hinged
leaves that snap shut when trigger hairs
are touched.
• Suction traps, unique to bladderworts,
are highly modified leaves in the shape
of a bladder with a hinged door lined
with trigger hairs.

19. Pitfall Traps

20. Pitcher Plant

21. Cobra Lily

22. Snap Traps

23. Venus Flytrap

25. Water Wheel

27. Flypaper

28. Sundew

31. Suction Traps

32. Bladderwort

36. Highly Sensitive
Plants

37. Mimosa Plant