Photosynthesis Flashcards
1
Q
what is the primary function of leaves
A
photosynthesis
2
Q
shorter wavelength is higher or lower energy
A
higher
3
Q
what types of light is required for photosynthesis
A
red and blue
4
Q
where does photosynthesis happen
A
mesophyll cells
5
Q
is all of the abosrbed light used for photosynthesis
A
no- only 4%
6
Q
more chloroplasts =
A
more photosynthesis
7
Q
pigments
A
light absorbing compounds
8
Q
the color of the pigment comes from
A
the wavelength of light that is reflected
9
Q
what light does chlorophyll relfect
A
green
10
Q
what light does carotenoids reflect
A
yellow, orange, reds
11
Q
anthocyanins
A
purple, pink, blue (antioxidants)
12
Q
chlorophyll captures light energy to initiate light rxn TF
A
T
13
Q
when chlorophyll absorbs light it __
A
changes its energy state
14
Q
chlorophyll + photon =
A
charged chlorophyll
15
Q
is the charged chlorophyll stable
A
no
16
Q
does chlorophyll bond to the photon
A
no
17
Q
what is the higher energy state for wavelengths of light - red or blue
A
blue is higher red is lower
18
Q
what are the pathways that the electron can return to ground state
A
heat, flourescence, energy transfer to molecule in close proximity,
19
Q
what type of light typically is released as heat
A
blue light - too high energy
20
Q
what happens when the photon is released by flouresence
A
light of longer wavelength lower energy
21
Q
photochemistry
A
light energy converted to chemical energy
22
Q
excitation energy can be transferred between _______
A
different chlorophyll pigments
23
Q
does energy get transferred or electrons
A
energy
24
Q
where does all of the energy go to
A
the reaction center
25
photochemistry
what happens at the reaction center
26
why do energy overflow pathways exist
if every photon is absorbed and converted to
27
efficiency depends on
temperature, water availability, nutrient availability
28
antenna complex
area where light energy is transferred between chlorophyll pigments to get to the reaction center
29
when do electrons come into play in photosynthesis
at reaction center
30
oxidation
lose electron
31
reduction
gain electron
32
what comes first- photosystem 1 or 2
2
33
antenna complex
light harvesting complex - has chlorophyll and funnels energy into reaction center
34
what funnels energy into the reaction center
the light harvesting complex
35
what happens at the reaction center
the antenna pigments transfer light energy to the reaction center
36
how many photosystems do plants have
2
37
where are the photosystems located
thylakoid
38
what happens in PS2
oxidation of water into O2 and H+
39
Explain the oxidation of water into O2 and H+
The electron is bounced off of PS2 and becomes oxidized (lose electron) which is hughly unstable. The water is stripped of an electron that restabilizes PS2. Water splits into Hydrogen and Oxygen gas.
40
PS2 is stabilized because
water is stripped of an electron
41
lumen
inside of thylakoid
42
plastoquinone
lipid soluble
43
every time this flashcard comes up please watch a video on the photosystems
j
44
4 general steps
1. oxidize water into O2 and H+
2. Electron transport chain
3. formation of NADPH
4. Formation of ATP
45
formation of NADPH steps
PS! loses electron which is transferred to reduce NADP+ to NADPH. Then, electrons move in direction of PS1 to stabilize it. Water is the electron donor
46
How does ATP Form
The electrochemical gradient from hydrogen ions trapped in lumen. This creates electrochemical gradient and ATP Synthase rotates
47
what is the rotary machine for ATP formation
atp synthase
48
where does photosynthesis occur
thylakoid membrane
49
what do we measure light in
PAR- photosynthetically active radiation
50
as light intensity increases, photosynthesis increases TF
True to a certain extent. very intense light can damage photosynthetic machinery
51
when you apply heat to fat it ____
melts
52
excess light stress prevents electron transpot chan and leads to
excess energt around Pn machinery
53
how does temperature affect the light reaction
when you apply heat to fat it melts. lipids in membrane are fluid at high temperatures so transfer reactions aren't as good.
Also protein denaturation
54
what are reactive oxygen species
molecular oxygen (not 02) its charged and wants to bond with something else.
55
what do the reactive oxygen species go after
chlorophyll
proteins
membranes
56
photooxidation
oxidation reduction induced by light
57
OILRIG
oxidation is loss reduction is gain
58
if electrons are given to B from A, A is the electron donor which is (oxidized or reduced)
oxidized
59
what is a strong oxidizer
a molecule that reacts with other things easily
60
how do plants change the lipids in the tails of the membranes to become liquid or gel like
by making their tails saturated or unsaturated. Response to stress
61
saturated fat
all carbons have hydrogens and therefore all carbon to carbon bonds are single bondsu
62
unsaturated fat
double bonds between carbons - easier to break
63
are thylakoid membranes saturated or unsaturated
unsaturated to be fluid in the thylakoid membrane
64
TF chlorophyll is super hydrophobic
T because its imbedded in the thylakoid membrane
65
how do plants prevent excessive light absorbtion
chloroplast movement from surface to side of cells
66
caroteniods
light harvesting complex
67
carboxylation
the linkage of carbon to something else that is in the plant
68
RuBisCo what does it do
pulls together CO2 and catalyzes reaction to attach it to RuBPw
69
what is the most abundant protein in the world
Rubisco
70
what is the rate limiting step in plants
Carboxylation of RuBP
RUBISCO!!!!!!!!
71
when rubisco links with oxygen what happen
photosynthesis doesnt happen
72
when rubisco links with carbon what happens
photosynthesis
73
is it hard for rubisco to tell the difference between carbon and oxygen gas
yes
74
what is the main factor on determining if carboxylation or oxygenation will happen with rubisco
the percentage of carbon and oxygen
75
respiration
using O2 and releasing CO2
76
respiration during photosynthesis is called
photorespiration.
77
what happens in photorespiration
rubisco takes up oxygen
78
photoxidation
during photosynthesis, when molecular oxygen turns into an oxygen radical
79
what is the biochemical step that produces sugars
Calvin cycle
80
watch video on photorespiration
-
81
rubisco + RuBP + Co2 later becomes
glucose
82
is photorespiration normal respiration
no
83
why does photorespiration happen
early atmosphere has little O2 and there was no selective pressure against binding O2
84
what conditions favor photorespiration
hot
dry
sunny
alter solubility ot decrease the CO2 levels
ANYTHING that closes stomata
85
what will plants do to reduce water loss in leaves
close stomata
86
what happens when the stomata close
they have lost the ability to transport air into the leaf. There is no limit on oxygen bc oxygen is produced in leaf. CO2 is limiting when stomata is closed
87
points of resistance to the diffusion of CO2 from outside the leaf to the chloroplasts
-whether stomata is open or closed
-membranes
-chloroplasts
88
the drops in concentration of CO2 on the outside keep it coming into the cell TF
T
89
what types of photosynthesis have little photorespiration
C4 plants
CAM Plants
90
Which plants are more resilient through drought and warm weather, C3 or C4
C4
91
what are the major differences that C4 plants have compared to C3
-mesophyll surrounds bundle sheath so carbon can't escape
- additional enzyme
- Concentrations of CO2 around RubBisCo
92
why is the bundle sheath in C3 plants
structural support
93
what carboxylates carbon in mesophyll cells in C4 plants i
PEP- phosphoenolpyruvate carboxylase
94
TF photorespiration reduces amt of sugars being produced
T
95
what does PEP do
fixes carbon so it doesnt bond with oxygen and only goes after CO2.
96
where is PEP located
mesophyll cells
97
how does C4 separate carbon fixation and carbon assimilation
by it happening in Mesophyll cell and then bundle sheath cell
98
watch video for C4 photosynthesis
-
99
PEP has affinity to O2 TF
F it doesnt
100
concentrated CO2 in the bundle sheath go straight to __________ in C4
rubisco
101
less photorespiration = higher or lower Pn efficiency
higher
102
How do C4 plants have higher water use efficiency
plants close their water to conserve water and the photo can still happen. Less water loss yet still efficient
103
how do C4 plants have higher nitrogen efficienct
less rubisco than C3 plants/ Dont have to worry about concentrating CO2 so less rubisco is needed. N content of C4 plants is less and they are able to use N more efficiently than C3 plants
104
who is more efficient when its not hot and dry C3 or C4
C3
105
CAM Photosynthesis where does it occur
Mostly mesophyll
106
what happens for CAM Photosynthesis at night
stomata open and take up CO2 to prevent water evap during the day.
107
what takes up CO2 in CAM Plants
pepcarboxylase
108
temporal separation
separating light and dark reactions
109
facultative CAM
plants that can turn cam on and off
110
Is growth the most important in arid environments
no defense is- cacti
111
