1. Atlantic Ocean in Winter
Fig. 6-1a p.92

2. Fig. 6-2, p.94

3. Fig. 6-3, p.95

4. p.97

5. upper epidermis photosynthetic cells leaf vein lower epidermis
a Zooming in on a
photosynthetic cell.
lower epidermis
Fig. 6-6a, p.97

6. two outer membranes of chloroplasts stroma part of thylakoid membrane
system bathed in stroma:
thylakoid
compartment,
cutaway view
b Chloroplast structure. No matter how highly folded, its thylakoid membrane system forms a single, continuous compartment in the stroma.
Fig. 6-6b, p.97

7. c In chloroplasts, ATP and NADPH form in the light-dependent stage of
sunlight O2
H2O
CO2
CHLOROPLAST
NADPH, ATP
light-
dependent
reactions
light-
independent
reactions
NADP+, ADP
sugars
CYTOPLASM
c In chloroplasts, ATP and NADPH form in the light-dependent stage of
photosynthesis, which occurs at the thylakoid membrane. The second stage,
which produces sugars and other carbohydrates, proceeds in the stroma.
Fig. 6-6c, p.97

8. electron transfer chain
light energy
light energy
electron transfer chain
NADPH
Photosystem II
Photosystem I
THYLAKOID
COMPARTMENT
THYLAKOID
MEMBRANE
oxygen
(diffuses away)
STROMA
Fig. 6-8b, p.99

9. a CO2 in air spaces inside a leaf diffuses into a photosynthetic
cell. Six times, rubisco attaches a
carbon atom from CO2 to the RuBP
that is the starting compound for
the Calvin–Benson cycle.
f It takes six turns of the
Calvin–Benson cycle (six
carbon atoms) to produce
one glucose molecule and
regenerate six RuBP.
6CO2
b Each PGA molecule gets
a phosphate
group from ATP, plus hydrogen
and electrons
from NADPH.
The resulting
intermediate is
called PGAL.
e Ten of the PGAL
get phosphate groups from ATP. In terms of energy, this primes them for an uphill
run—for the
endergonic synthesis reactions that
regenerate RuBP.
6 RuBP
12 PGA 12
ATP
6 ADP
Calvin-Benson
cycle
12 ADP + 12 Pi 6
ATP 12
NADPH
4 Pi
12 NADP+
d The phosphorylated
glucose enters reactions that form carbohydrate
products—mainly sucrose, starch, and cellulose.
c Two of the twelve PGAL
molecules combine to form
a molecule of glucose with
an attached phosphate group.
10 PGAL
12 PGAL
1 Pi
phosphorylated glucose
Fig. 6-10, p.101

10. Fig. 6-11, p.102

11. Fig. 6-12, p.103

12. end products (e.g., sucrose, starch, cellulose)
Light-
Dependent
Reactions
sunlight
H2O O2
ADP + Pi
ATP
NADP+
NADPH
Light-
Independent
Reactions
Calvin-Benson cycle
CO2
H2O
phosphorylated glucose
end products (e.g., sucrose, starch, cellulose)
Fig. 6-13, p.104

13. p.104

14. p.105a