Download Biology Chapter 7

Biology
Chapter 7
Fill-in-the-Blanks
(1) __________obtain carbon and energy from the physical environment; their carbon source is
(2)___________. (3) ____________ autotrophs obtain energy from
sunlight. T. (4) ___________demonstrated that aerobic bacteria moved to the regions of a strand
of Spirogyra where red and (5) __________light was falling on the strand; O2 was produced
here. (6) _________________ feed on autotrophs, each other, and organic wastes;
representatives include (7) _________________, fungi, many protistans, and most bacteria.
Although energy stored in organic compounds such as glucose may be released by several
pathways, the pathway known as (8) ___________________________ releases the most energy.
9. In the space below, supply the missing information to complete the summary equation for
photosynthesis:
12 ________ + CO2 —> + O2 + C6H12O6
10. Supply the appropriate information to state the equation for photosynthesis (above) in words:
(a) _____________________ molecules of water plus six molecules of
(b)____________________ (in the presence of pigments, enzymes, and sunlight) yield six
molecules of (c)______________________ plus one molecule of (d) ____________________
plus (e)_________________________ molecules of water.
The two major sets of reactions of photosynthesis are the (11)________________ reactions and
the (12) ________________________ reactions. (13)______________________
and (14) ________________________ are the reactants of photosynthesis, and the end product is
usually given as (15) _________________. The internal membranes and channels of the
chloroplast form the (16)________________________ membrane and are organized into stacks,
called (17) ____________________________. Spaces inside the thylakoid disks and channels
form a continuous compartment where (18) _______________________ions accumulate to be
used to produce ATP. The semifluid interior area surrounding the thylakoid is known as the
(19) ___________________________ and is the area where the products of photosynthesis are
produced. Although glucose is commonly listed as the end product of photosynthesis, little
glucose is actually found in the cells, since the glucose phosphate produced is quickly converted
into (20) ________________________, (21) _____________________,
and (22) ________________.
a. thylakoid membrane
23. ____ Light-independent reactions
24. ____ Sugars are assembled
25. ____ Light-dependent reactions
26. _____ ATP production
27. _____ Carbon dioxide provides the carbon
b. stroma
28. _____ Sunlight energy is absorbed
29. _____ Water molecules are split
30. _____ NADPH delivers the hydrogen
received from water
31. _____ Oxygen is formed
Fill-in-the-Blanks
The light-capturing phase of photosynthesis takes place on a system of (1) _________
membranes. A(n) (2) _______________ is a packet of light energy. Thylakoid membranes
contain (3) ______________________, which absorb photons of light. The principal pigments
are the (4) __________________, which reflect green wavelengths but absorb (5) ____________
and (6) _____________________ wavelengths. (7)__________________ are pigments that
absorb violet and blue wavelengths but reflect yellow, orange, and red.A cluster of 200 to 300 of
these pigment proteins is a(n) (8) __________________________.
Matching
Choose the most appropriate answer.
9. ____ Chlorophyll
10. ____ accessory pigments
11. _____ carotenoids
12. ____ violet—blue—green—yellow—red
13. ____ photons
14. ____ Chloroplast
15. ____ phycobilins
16. ____ thylakoid
17. ____ pigments
A. Packets of energy that have an undulating motion
through space
B. The two stages of photosynthesis occur here
C. Molecules that can absorb light
D. Absorb violet and blue wavelengths but transmit
red, orange, and yellow
E. Visible light portion of the electromagnetic spectrum
F. Pigments that transfer energy to chlorophyll a
G. Absorb violet-to-blue and red wavelengths; the
reason leaves appear green
H. Red and blue pigments
I. The site of the first stage of photosynthesis
Labeling
The following diagram illustrates noncyclic photophosphorylation. Identify each numbered part of the illustration .
2.__________________________
3.__________________________
4.__________________________
5._______________________________
6._______________________________
7._______________________________
8._______________________________
Fill-in-the-Blanks
ATP forms in both the cyclic and noncyclic pathways. When (9)___________________ flow
through the membrane-bound transport systems, the systems also pick up hydrogen ions (H )
outside the membrane and shunt them into the (10)___________________ . compartment. This
sets up Hf-concentration and electric (11) ___________________ across the membrane.
Hydrogen ions that were split away from (12)___________________ molecules increase the
gradients. The ions respond by flowing out through the interior of (13) ___________________
proteins that span the membrane. Energy associated with the flow drives the binding of unbound
phosphate (F1) to ADP, the result being (14) ___________________ . The above description is
known as the (15)___________________ theory of ATP formation. The noncyclic pathway also
produces (16) __________________ by using (17) ___________________ from water and H
ions from the thylakoid compartment to reduce NADP.
Label and Match
Identify each part of the following illustration. Complete the exercise by
matching and entering the letter of the proper function description in the parentheses following
each label.
1. ________________________(
2. ________________________(
3. ________________________(
4. ________________________(
5. ________________________(
6. ________________________(
7. ________________________(
8.________________________ (
9.________________________ (
)
)
)
)
)
)
)
)
)
A. A three-carbon sugar, the first sugar produced; goes on
to form sugar phosphate and RuBP
B. Typically used at once to form carbohydrate end products of photosynthesis
C. A five-carbon compound produced from PGALs; attaches to incoming CO2
D. A compound that diffuses into leaves; attached to RuBP by enzymes in photosynthetic cells
E. Includes all the chemical reactions that “fix” carbon into an organic compound
F. Three-carbon compounds formed from the splitting of the six-carbon intermediate compound
C. A molecule that was reduced in the noncyclic pathway; furnishes hydrogen atoms to construct
sugar molecules
H. A product of the light-dependent reactions; necessary in the light-independent reactions to
energize molecules in metabolic pathways
I. Includes all the chemistry that fixes CO2 converts PGA to PGAL and PGAL to RuBP and sugar
phosphates
Self-Quiz
_____ 1. The electrons that are passed to NADPH
during the noncyclic pathway of photo synthesis were
obtained from
a. water b. CO 2 c. glucose d. sunlight
_____ 2. The cyclic pathway of the light- dependent
reactions functions mainly to _______________ .
a. fix CO2
b. make ATP
c. produce PGAL
d. regenerate ribulose bisphosphate
____ 3. Chemosynthetic autotrophs obtain en
ergy by oxidizing such inorganic sub
stances as ________________ .
a. PGA b. PGAL c. sulfur
d. water
_____ 4. The ultimate electron and hydrogen acceptor
in noncyclic photophosphorylation is
_______________ .
a. NADP b. ADP c. O 2 d. H 2O
____ 5. C4 plants have an advantage in hot, dry
conditions because _______________
a. their leaves are covered with thicker wax layers than
those of C3 plants
b. their stomates open wider than those of C3 plants,
thus cooling their surfaces
c. they have a two-step CO2 fixation that reduces
photorespiration
d. they are also capable of carrying on photo-respiration
_____ 6. Chlorophyll is
a. on the outer chloroplast membrane
b. inside the mitochondria
c. in the stroma
d. in the thylakoid membrane system
_____ 7. W hich of the following is applicable to C3
plants?
a. At the end of carbon fixation, the intermediate
compound is PGA.
b. At the end of carbon fixation, the intermediate
compound is oxaloacetate.
c. They are more sensitive to cold temperatures than are
C4 plants.
d. Corn, crabgrass, and sugarcane are examples of C3
plants.
____ 8. Plant cells produce 0 2 during
photosynthesis by .
a. splitting CO 2
b. splitting water
c. degradation of the stroma
d. breaking up sugar molecules
_____ 9. Plants need and _______________ to carry on
photosynthesis.
a. oxygen; water
b. oxygen; CO 2
c. C0 2 H 20
d. sugar; water
_____ 10. The two products of the light-dependent
reactions that are required for the light-independent
chemistry are _____________ and
a. C0 2; H 20
b. 02;
NADPH
c. 0 2; ATP
d. ATP; NADPH