asd

1. BIOLOGY
Campbell • Reece • Urry • Cain • Wasserman • Minorsky • Jackson
© 2015 Pearson Education Ltd
TENTH EDITION
Global Edition
Lecture Presentation by
Nicole Tunbridge and
Kathleen Fitzpatrick
11
Photosynthetic
Processes

2. © 2015 Pearson Education Ltd
The Process That Feeds the Biosphere
a) Photosynthesis is the process that converts solar
energy into chemical energy
b) Directly or indirectly, photosynthesis nourishes almost
the entire living world

3. © 2015 Pearson Education Ltd
a) Autotrophs sustain themselves without eating
anything derived from other organisms
b) Autotrophs are the producers of the biosphere,
producing organic molecules from CO2 and other
inorganic molecules
c) Almost all plants are photoautotrophs, using the
energy of sunlight to make organic molecules

4. © 2015 Pearson Education Ltd
Figure 11.1

5. © 2015 Pearson Education Ltd
Figure 11.1a
Other organisms also benefit from
photosynthesis.

6. © 2015 Pearson Education Ltd
a) Photosynthesis occurs in plants, algae, certain other
unicellular eukaryotes, and some prokaryotes
b) These organisms feed not only themselves but also
most of the living world

7. © 2015 Pearson Education Ltd
Figure 11.2
(a) Plants
(b) Multicellular alga
(c) Unicellular eukaryotes
(d) Cyanobacteria
(e) Purple sulfur
bacteria
40
μm
1μm
10μm

8. © 2015 Pearson Education Ltd
a) Heterotrophs obtain their organic material from other
organisms
b) Heterotrophs are the consumers of the biosphere
c) Almost all heterotrophs, including humans, depend on
photoautotrophs for food and O2

9. © 2015 Pearson Education Ltd
a) Earth’s supply of fossil fuels was formed from the
remains of organisms that died hundreds of millions
of years ago
b) In a sense, fossil fuels represent stores of solar
energy from the distant past

10. © 2015 Pearson Education Ltd
Figure 11.3

11. © 2015 Pearson Education Ltd
Concept 11.1: Photosynthesis converts light energy to
the chemical energy of food
a) Chloroplasts are structurally similar to and likely
evolved from photosynthetic bacteria
b) The structural organization of these organelles allows
for the chemical reactions of photosynthesis

12. © 2015 Pearson Education Ltd
Chloroplasts: The Sites of Photosynthesis
in Plants
a) Leaves are the major locations of photosynthesis
b) Chloroplasts are found mainly in cells of the
mesophyll, the interior tissue of the leaf
c) Each mesophyll cell contains 30–40 chloroplasts
d) CO2 enters and O2 exits the leaf through microscopic
pores called stomata

13. © 2015 Pearson Education Ltd
a) A chloroplast has an envelope of two membranes
surrounding a dense fluid called the stroma
b)Thylakoids are connected sacs in the chloroplast
which compose a third membrane system
c) Thylakoids may be stacked in columns called grana
d)Chlorophyll, the pigment which gives leaves their
green colour, resides in the thylakoid membranes

14. © 2015 Pearson Education Ltd
Figure 11.4
Stroma Granum
Thylakoid
Thylakoid
space
Outer
membrane
Intermembrane
space
Inner
membrane
20 μm
Stomata
Chloroplast Mesophyll
cell
1 μm
Mesophyll
Chloroplasts Vein
Leaf cross section
CO2 O2

15. © 2015 Pearson Education Ltd
Figure 11.4a
Leaf cross section
Stomata
Chloroplast
Mesophyll
Chloroplasts Vein
Mesophyll
cell
20 μm
CO2 O2

16. © 2015 Pearson Education Ltd
Figure 11.4b
Chloroplast
Stroma Granum
Thylakoid
Thylakoid
space
Outer
membrane
Intermembrane
space
Inner
membrane
1 μm

17. © 2015 Pearson Education Ltd
Tracking Atoms Through Photosynthesis: Scientific
Inquiry
a) Photosynthesis is a complex series of reactions that
can be summarized as the following equation:
6 CO2 + 12 H2O + Light energy → C6H12O6 + 6 O2 + 6 H2O
a) The overall chemical change during photosynthesis is
the reverse of the one that occurs during cellular
respiration

18. © 2015 Pearson Education Ltd
The Splitting of Water
a) Chloroplasts split H2O into hydrogen and oxygen,
incorporating the electrons of hydrogen into sugar
molecules and releasing oxygen as a by-product

19. © 2015 Pearson Education Ltd
Figure 11.5
Reactants:
Products:
6 CO2 12 H2O
C6H12O6 6 H2O 6 O2

20. © 2015 Pearson Education Ltd
Photosynthesis as a Redox Process
a) Photosynthesis reverses the direction of electron flow
compared to respiration
b) Photosynthesis is a redox process in which H2O is
oxidized and CO2 is reduced
c) Photosynthesis is an endergonic process; the energy
boost is provided by light