Bot 311 Study Guide Photosynthesis Name ______________________________________
The Visible region of
the spectrum is also known as PAR which means P_____________________ly
A______________e R_______________________ion. It spans the region from ________
to ________ nanometers or the B________e to R___d spectral regions.
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A] Chlorophyll
Absorption B]
Solar Radiation Output C]
Solar Radiation that Penetrates our Atmosphere |
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When a C_________________l M____________________e absorbs a photon of
L___________t, one of its E________________s makes an energy transition to an
E________________ed S______________e. This represents an increase in
P___________________l E_____________y.
During Photosynthesis ____2 is captured and ____2 is produced. It takes L___________t & 1000s of C____________________l molecules to produce 1 molecule of ____2. Studies have shown that there are 2 R_________________n C______________s located in the T____________s that H________________t L_____________t and produce _____2. These are called PS __ and PS __. These are linked by E____________n C______________rs. Each PS has a special C_______________l a molecule at its core. These R___________n C__________r C________________s are known as P_____ and P_____ because they strongly a__________b L_____________t at these W__________________s. ______2 fixation occurs in the S___________a of the Chloroplast.
Light Harvesting 1,2,3
..4
Light is a_____________d by
a___________a p_____________s and its energy is t____________d to the R____________n
C____________r C________s. This e__________s an e____________n in each. These e_____________s are
transferred to e_____________n c____________s. The
electron from PS r______________s the
e______________n lost by PS ___. An e___________n is taken
from W___________r to replace the missing PS ___ e_____________n. This
leads to O___________n E________________n. The PS ___ e_____________n
is used to R_______________e N________ to N__________ (NADP effectively
gains an electron). N__________ is used to Reduce C____________n
D__________e in the S_________a of the Chloroplast.
The
Oxidation of Water produces
an H_______________n ion (Proton). Protons are also transported across the
T_______________d during E_______________n T____________________rt. Protons
accumulate in the T_________________d L_________________n. This makes one side
of the membrane A___________c because it is high in Protons. An A___Synthase in
the T________________d Membrane uses the Proton Gradient to produce ___ ___
___.
OVERALL,
The immediate products of Light
Harvesting are O___________n, A___P &
N__________H. The latter two are used to R_____________e C___________n
D___________e in the S____________a.
The
A____________a
P______________s & Light Harvesting Complexes are conceptually organized like a F___________l with a S____________e
at the b_____________m.
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A]
Chlorophyll A B]
Chlorophyll B C]
Carotenoids D]
Reaction Center |
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The
A_______________a P______________s in Land Plants and Green Algae are
Chlorophyll ___ & ___, plus various C______________s. C________________s
absorb in the b__________e-g__________n region of the spectrum and
b____________n the range of w_________________s that can be harvested for
Photosynthesis. Other organisms, like Red Algae (Rhodophyta) have different
A______________a P_______________s which we will study later.
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A]
Chlorophyll A B]
Chlorophyll B C]
Carotenoids D]
Bacteriochlorophyll |
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There
are three basic events which
characterize _____2 F_________________ion.
These are C_________________n, R_______________n &
R___________________n. The first step involves the addition of _____2 to a
5-C___________n Acceptor. This leads to the production of two 3-C___________n
molecules. The next step involves the R____________n of the 3-C_____________n
molecule into a C__________________te. The final step is a complex series of
reactions, which R___________________s the 5-C________________n
A________________r R_______P.
The
enzyme that adds CO2 to RUBP is called R____________________O (Ribulose
Bisphosphate Carboxylase/Oxygenase). It has a dual function. It can Carboxylate
RUBP (Photosynthesis) or it can O______________e it (P__________________n).
This latter results in the loss of ______2! Both of these reactions involve the
same active site, and the substrates directly C_________________e with one
another. Under typical ambient conditions the ratio between CO2 fixation &
Oxygenation is ___:1. Photorespiration reduces the efficiency of photosynthesis
by as much as ______%. Concentrations of _____2 & ______2, plus the Leaf
T________________e regulate the balance between P_______________s &
P____________________n. C____________n D____________e concentrations are always
much lower than O___________n levels inside leaves and in the atmosphere.
L__________f T________________e rises during photosynthesis, especially under
dry, sunny conditions. This favors P__________________n over
P_______________________s.
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Place
the Letter for the Best
Match inside the Boxes A]
Bundle Sheath B]
Photosynthetic Mesophyll |
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There are two types
of C___________________s in the M_________________l & B_____________e S_____________h cells of C4
Leaves.
Chloroplasts
with G___________a are observed in M______________l Cells. Chloroplasts without
Grana are found in the B______________e S____________h cells. S_______________h
accumulates in the Bundle Sheath Chloroplasts during active periods of
P___________________s. It is transported to the Phloem during the night.
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Place
the Letter for the Best
Match inside the Boxes A] Mesophyll
Chloroplast B] Bundle Sheath
Chloroplast |
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Carbon
Path in C4 Psyn: _________2
crosses the Cell Wall and Plasmalemma of a M______________l C___________l. It
is fixed by ______ Carboxylase to form a 4-C__________n Acid like Malate. This
occurs in the C__________________m. The 4-Carbon Acid is t_________________d
via P____________________a to a B_____________e S_______________h C________l
where ______2 is released and fixed by R____________O
using the C____Cycle. PEP is reformed and is t________________d back to the
M________________l Cell where it can accept another _________2.
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Place
the Letter for
the Best Match inside the Boxes A] PEP (used twice) B] PEP Carboxylase C] CO2 (used twice) D] Cell Wall E] Plasmalemma F] Plasmodesmata G] Malate H] RUBISCO I] 3 Carbon UnitLabel the
Bundle Sheath Cell & the Mesophyll Cell |
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C4
plants photosynthesize better than C3 plants under d___y h____t conditions. The
greater a__________y of PEP Carboxylase for ____2 means that the enzyme is
s_____________d at low ______2 levels. Consequently, stomata may be
c________________d for longer periods of time with C___ plants versus C____
plants. This helps to conserve w________r. PEP Carboxylase is not inhibited by
____2 and is incapable of P_________________n. This C4 process c___________________s ______2 in the
vicinity of R_____________O in the B______________e S______________h
C_________s where the C_______________s do not produce _____2 because they lack
G________a. This favors P__________________s over P______________________n in
the Bundle Sheath Cells.
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Place
the Letter for
the Best Match inside the Boxes A]
C3 Plant B]
C4 Plant |
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Leaves
are Green because they either r_____________________t or a__________________b
other w__________________hs of l______________t.
Some
Epidermal cells are able to f____________s light on p_________________ic
M___________________l c____________s.
The
number of P_____________e layers is related to the amount of light reaching the
leaves. Many layers are present in b___________t l____________t environments
while one or two are found in d___m light. P_____________e Cells have
s___________l i______________r s______________s. However, their shape provides
a lot of s_____________e area for g___s e_______________e without
e_______________e a___r s_____________s. Consequently, they have the best Shape
& Organization for photosynthetic efficiency. Multiple P_________________e layers are
found in plants which inhabit d_______y environments.
The
Sieve Effect is due to the fact that c_______________l is contained in
C_____________________s rather than being dispersed uniformly throughout the
cell. Light Channeling occurs because C_______________s are distributed
in the o____________________t C___________________m. This leaves a
t_____________________t central region occupied by the V____________________e.
Light is channeled through without being absorbed. Light Channeling also occurs
in the A_________________t . Light Scattering also occurs in the
A________________t. This diffuses the light & i________________s the path of photons within the leaf This
i_______________s the probability of its a_________________n. Photon paths
within leaves can be increased by a factor of F__________R! The S_____________y
M_________________l has large I_________________r S______________s and
irregularly o_______________d cells. Both of these factors i_______________e
the light path within leaves. This makes light a______________n more likely!
Leaves
have many adaptations which can i__________________t the a_________________n of
e________________s light. These are primarily found in the E_______________s
but may also include other tissues. Some of these r_____________t light while
others may s__________r or a_____________b light. T_________________s tend to
r_________________t light, as may a thick W__________y layer or
C__________________e. Irregularly E__________________d C__________s may also be
reflective.
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Place the Letter for the Best Match in the Boxes A] Light Channeling B] Vacuole C] Chloroplasts |
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Kukui
Trees are easily identified due to their highly r________________e leaves. This
is due the presence of dense, multicellular T______________s. The reflection of
ohi'a lehua leaves is due to a dense layer
of T__________________s. These typically occur on the l______________r
surface of the leaf but can be abundant on the u_______________r surface as
well. The Leaves of Ohi'a lehua have a multilayered H__________________s which
may also decrease the amount of light reaching the P_____________________ic
M___________________l.
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Place the Letter for the Best Match in the Boxes A]
High Light B]
Low Light |
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The
disposition of the C___________________s can control the amount of
L______________t absorbed by leaves. Chloroplasts are a_______________d and d_____________d
p________________________r to the light when light levels are l_____w. This
achieves m____________________l a______________________n. The converse is true
under h___________h l_____________t conditions. Chloroplast orientation can change
the amount of light absorbed by ________%.
Chloroplast
movement also occurs in A_________e. Species of Mougeotia have flat
ribbon-like chloroplasts These are p________________r to the L_______________t
at l_____w irradiances. They have a p______________l orientation at
h_____________ irradiances.
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Place the Letter for the Best Match in the Boxes A]
High Light B]
Low Light C]
Chloroplast |
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Some
plants can change the o________________________n of their leaves
t_______________s the Sun. This is called Solar Tracking. In some cases
this adjustment is c___________________s throughout the day so the leaf blades
are always p______________________r to the sun's rays. In many cases the leaves
of solar-tracking plants have a P___________________s. This is a swollen part
of the P_______________e and may occur where it joins the stem, the leaf blade
or BOTH. The P_____________s contains M__________r C________s which
control the disposition of the petiole and consequently, the blade. Solar
Tracking may be most beneficial in the early m_____________________g and late
a______________n when the w___________r b_________________e of the leaf is
f_________________e for P___________________s but the amount of available
l_____________t is low. This is similar to what occurs when the V________s
F_____________p snaps shut. This is controlled by changes in T_____________r
P__________________e. The shape of G____________d C____________s is regulated
in a similar manner.
Shady
zones may only receive _____% of the PAR received in open environments. Shade
Leaves have more C_______________l per R_____________n C______________r, and
more C__________________l b which is an A____________a P_________________t that expands the
spectral region over which L_______________t can be
a_______________________d. Plants grown
at low light have greatly reduced R_____________________n rates, which allows
them to reach their Light C_______________n Point (LCP) at l___w irradiance.
The LCP is the irradiance at which the _______2 fixed by Photosynthesis is
equal to the ______2 lost by Respiration. The Light S______________n Point is
reached when further increases in i_________________e fail to i_______________e
_____2 fixation. As Shade leaves are S___________________d at lower
i___________________s than sun leaves. Shade leaves can not s_________________e
at high irradiances!
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Place
the Letter for the Best Match in the Boxes A]
Sun Leaf B]
Shade Leaf C]
Compensation Point D]
Saturation |
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Evaporative
or Latent heat loss occurs when w___________r evaporates from the
c________l w___________s of leaf cells. This is due to the latent heat of
evaporation. T______________________n is the major source of evaporative heat
loss. Sensible or Perceptible heat loss occurs when captured s_____________t
wavelength light energy is r_______________d as l_________g wavelength
irradiation. Plants that primarily use sensible heat loss to shed excess energy
must keep their s_________________a closed. These plants must endure very high
leaf temperatures in order to survive. This obviously restricts CO2 uptake and
leads to s________w growth.
