Photosynthetic Flashcards
Calvin cycle (food synthesis)
Aka
Discovery
Present in ___________
C3 cycle
Earlier scientist
Primary acceptor 2carbon compound
Co2+1°—RUBISCO(Carboxy)—> 3 PGA
1°- 2 carbon compound
3phosphoglyceric acid
Rubulose1,5bisphosphate carboxylase oxygenase
Later on Co2+1°—RUBISCO(Carboxy)—>
2[3PGA]
1° ketose sugar (5C)
Present in all plants
C4 cycle
_______ Seen as 1° product in ________ and _________ plants
Oxaloacetic acid
Sugarcane
Maize
Photorespiration
Aka
Wasteful process because
Happens when conc of ______greater than ______
Reaction
C2 cycle
> no co2 fixation
ATP consumed
loss of carbon
no sugar synthesis
in presence of light , daytime , green cell
Oxygen
carbondioxide
Reaction
RUBP+O2-‐—–rubisco—–>
phosphoglycolate+ pGA
1°»_space;> RUBP
Phosphoglycolate - 2 carbon
RUBISCO > OXYGENASE
CALVIN CYCLE[biosynthetic phase]
Discovered in
Technique to study
Main Enzyme
1° acceptor
1° product
No.of co2 energyconsumed turns
Process
Total energy consumed
> Chlorella (alage)
> chromatography/ radioisotropy
> rubisco
ribulose1,5 bisphosphate
3PGA
1co2»_space; 3ATP 2NADPH»1 turn
6co2» 18 atp 12nadph»_space;6 turn
Multiply everything w 6
A.Carboxylation
Co2 + rubp —–rubisco—> 2[3pga]
Intake of 1 h2O
B. REDUCTION
2pga 2atp—>adp
2[1,3 bisphosphoglyceric acid]
2BPGA 2NADPH—->NADP+ 2[3PGAL]
3PGAL glyceradalehyde-3-p
C. Regeneration
Total 2×6 = 12pgal
2pgal [2×3 carbons] move out to form glucose
10pgal [10×3 carbons ]—6atp—>
Converted into 6rubp [6×5 carbons]
Total energy
6 turns
0 + [12atp +12nadph] +6atp
18atp 12 nadph
1turn
0+[2atp+2nadph] + 1atp
3atp & 2nadph
C4 cycle
Plant
Scientist
1st product
No.of COOH grp
Mainly present in monocot but also present in _________(dicot)
> Sugarcane maize sorghum
> hatch & slack
> Oxaloacetic acid
cooh-2
> atoiplex
Vascular bundle surrounded by layers of ____________
Description of the above mentioned cells
Bundle sheath surrounded by ___________
Rubisco found in
Chloroplast
Main Enzyme + location
KRANZ anatomy?
In what type of plants
1.Bundle sheath cells [C3 + C4]
>cell wall - thick + impermeable to gas
>intercellular space- absent
2.mesophyll cells [c3 & c4]
- RUBISCO
C3- mesophyll
C4 - bundle sheath - Chloroplast
C3 MONOMORPHIC
> mesophyll»_space; present
> bundle sheath»_space; absent
C4 DIMORPHIC
>mesophyll»_space; present »_space; small
>bundle sheath»_space; present»_space; large
5.Main Enzyme + location
C3 - RUBISCO»_space;MESOPHYLL
C4- PEPcase»_space; mesophyll
KRANZ ANATOMY
>only c4
>bundle sheath cells arranged in wreath like manner
C3 vs c4
1.Primary acceptor
2.Main Enzyme
3.1°product
4.1st Carboxylation location
5. Decarboxylation
6. 2nd carboxylation
7.fixation of 1C energy
8. Cell in which Calvin cycle takes place
9. Cell of 1st carboxylation
10.type of cells that fix Co2
11. Rubisco+ cells containing it
12. Pepcase
13.Photorespiration at low light int
14.Photorespiration at high light int
15.Photorespiration at low co2 conc
16.photorespiration at high co2 conc
17.co2 fixation rate at high light conditions
18 optimum temp
19 examples
C4 cycle
Process in Mesophyll &bundle sheath
____turn in c4 cycle= ______turn in c3
Total no.of atp nadph used
No.of c turns energy
1 = 1
1.RUBP / PEP[phosphoenolpyruvate] c3
2. Rubisco / PEPcase [pep carboxylase]
3. 3pga/ OAA [4 C]
4. In mesophyll / mesophyll
5. - / bundle sheath cells
6. -/bundle sheath cells
Hence C4 shows double carboxylation
7.3atp 2nadph / 5atp 2nadph[more consumed in C4]
8.
>mesophyll
>bundle sheath
9.
> single»_space; mesophyll
> double 1. Mesophyll 2. Bundle sheath
10
>mesophyll
> mesophyll + bundle sheath
11 .
Yes mesophyll
Yes bundle sheath
12.
Yes
Yes
13
Negligible
Negligible
14
Yes
Negligible
15
Yes
Negligible
16
Negligible
Negligible
17
Low
High[no photoresp]
18
15-20
35-40
19
Wheat rice barley
Sugarcane maize sorghum
C4 cycle
Mesophyll cells
>1st carboxylation CYTOPLASM
Co2 + PEP 3C —PEPcase—> OAA[4C]
> OAA —-> malic acid [4C]
Goes to bundle sheath cells via plasmodesmata
Bundle sheath
In Chloroplast
Malic acid —–> pyruvic acid [3C]
Co2 released
This co2 takes part in c3 cycle
Regeneration
Pyruvic acid goes to Mesophyll CYTOPLASM and gets convert into PEP 2ATP —> 2ADP
C3 is a part of c4 cycle
5atp 2nadph for fixation of 1 co2
1 5atp 2nadph
6 30atp 12nadph
Co2 > o2
Co2 = o2
Co2<o2
condition
O2 & Co2 binding for rubisco is ______
Rubp carboxylation
Normal process»_space; glucose synthesis
Co2<o2>>> phosphoglycolate + PGA</o2>
Competitive
PHOTORESPIRATION
Organelles
Happens in ______ and absent in _____
Reason. Therefore yield is better in _______
[ co2 affinity , limiting factor ]
Chloroplast
Peroxisome
Mitochondria
C3 plants , c4 plants , C4 plants
- co2 affinity
C4 PEPCASE > c3 rubisco
2.limiting factor
Co2 limiting in c3 and not limiting in c4 plants as malic acid to pyruvic acid releases co2 hence co2 conc will always be more around rubisco in c4 plants [intracellular co2]
1.Rate of photosyn imp in determining
2.Rate Under influence of ______ as well as _______ factors
3.Greater chloroplast _____ photosyn
4.leaf larger ______ photosyn
5. Mature leaf _______photosyn
6. Senescent leaf ________photosyn
7. More the mesophyll cell _____photosyn
8. Internal factors dependent on _________ & ___________
1.yield of plants (crop plants too)
2.Internal, external
3. Greater
4.greater
5. Greater
6. Lesser [chloroplast destruction]
7. Greater [more chloroplast]
8. Genetic predisposition & growth
External factors
1.rate determined by
Major External factor = ______ factor= factor available at _______ levels
2. Law of limiting factors
>statement
>given by
3.
Rare limiting factor = _______
Major limiting factor =_______
A.LIGHT
Intensity
Quality
Duration
Light saturation occurs at _____%of full sunlight
BCO2
Conc in atmp
Response by c3 & c4
Greenhouse application example of plants
C.temperature
Reason why temp sensitive
Optimum temp for c3 and c4
Optimum temp also depends on habitat _______plants have higher optimal temp than _______plants
D. Water [indirectly]
- Limiting , sub optimal
2
>if chemical process affected by more than one factor rate determined by nearest minimal value
>blackman - Light
Co2
LIGHT
>suboptimal level linear relationship
As light limiting factor
> optimal level 300nm max photosyn
> saturation level at very High intensity no further increase [rate decreases]
-other factors limiting
-destruction of chloroplast
-c3 shows photorespiration
Quality
blue & red light
400-700nm
Light saturation occurs at 10_%of full sunlight
B. CO2
0.03-0.04% max upto 0.05 will show increase in rate
Low light co2 conc max
C3 low rate
C4 low rate
High light (normal)
C3 450 co2 high rate
C4 360 co2 high rate
This logic is used to grow c3 plants
For better yield in higher c02 for
TOMATO + BELL PEPPER
Temperature
Dark rxn temp sensitive cuz enzymatic
Light rxns are also temp sensitive but much lesser extent
C3 lower temp 15-20/25°c
C4 higher temp 30-35
Tropical , temperate
Water
Water stress causes closure of stomata
decreases co2 availability
Wilting»_space;surface area+metabolic activity reduction
Define
Type of process and metabolism
Light vs dark rxn
Location
Energy
Dependence on light
Physcliochemical process where light energy converted into chemical energy
Endergonic process
Anabolic metabolism
Grana>thylakoid stroma
Membrane
Pigment
Assimilatory energy used
Power for food syn
Atp + nadph formed
Depends on light depend
InDirectly on light
Depends on product
of Light rxn
Experiments
- Role of chlorophyll
- Role of light
3.role of co2 - PRIESTLY
>co2 produced
>co2 purified
>o2 availability
>candle extinguish
>mouse
5.ingenhousz
6.Engelmann
>exp
>PAR
>blue and red are known as ________
Cuz rate of photosyn max there
Absorption spectrum
7. Middle of 19th century
8. VAN NIEL
Exp on
Rxn
9. Ruban& kaman
10.Von sachs
- Chlorophyll
Light on variegated leaf plus iodine
Starch test [blue black colour]
Green plant iodine test blue black result due to presence of glucose
Photosynthesis due to chlorophyll - Light
Leaf part covered by black paper
Exposed part > iodine test> blue black> Starch > photosyn > light
3.role of co2
Leaf in container > in container KOH
»co2 absorbed»_space; no colour in iodine test > no Starch > no photosynthesis > no co2
- Priestly exp
Box A mouse candle only
Box B mouse candle mint plant
Plant purifies foul air
Co2 produced in A and B
Co2 purified in B
O2 avaliable in B
Candle extinguish in A
Mouse die in A
- Ingenhousz
Highlighted the rest of priestly w aquatic plant HYDRILLA
Box A aquatic plant under light
Box B aquatic plant in no light
Air bubbles seen in A
6.Engelmann
Suspension of Aerobic bacteria
Cladophora( green) alage
Visible light thru prism
Aerobic bacteria most at region of red and blue light as o2 max there cuz photosynthesis max there
Visible light»involved in photosynthesis»_space; hence called PAR
Photosynthetic active radiation
Action spectrum
Absorption spectrum [red & blue]
Max light absorbed by pigments
- Co2+h2o—–> carbohydrate
- Van niel
Oxygen released comes from h2o
Exp on purple & green sulphur bac
Co2 + 2h2s —light–> ch2o + h2o + s2
Non oxygenic as bac doesn’t use h20
Co2 reduced
In green plants h20 used and oxygen released hence oxygen produced is from water
- Ruban & kaman
Radioisotopes
Co2¹⁶ + H2O¹⁸»_space;>O2¹⁸
EXPERIMENTAL PROOF OXYGEN COMES FROM WATER - Von Sachs
Starch is 1st visible product of photosyn
Chlorophyll >chloroplast > green plants >photosyn >glucose >starch
Photosyn takes place in stem
In ________&________
Euphorbia
Opuntia
Alignment of chloroplast in mesophyll cells
Low intensity
High intensity
- Low intensity
Chloroplast arranged parallel to leaf surface - High intensity
Chloroplast arranged perpendicular to leaf surface [to prevent destruction]
Pigments (fat soluble) separated by __________(technique)
Colour seen for given pigments
Chla
Chlb
Xanthophyll
Carotene
Main Photosynthetic pigment [directly involved]
Accessory pigment [indirectly involved]
Paper chromatography
Chla bluish green
Chlb yellowish green
Xanthophyll yellow
Carotene yellow to orange
Main > chla
Accessory >
carotenoids [Carotene + Xanthophyll]
Chl b
Chlorophyll
[Hydrophilic/phobic
Chemical composition]
Head
Tail
Head
> hydrophilic
> porphyrin Head > 4 pyrrole ring
2nd pyrrole ring 3rd carbon has methyl —> chla
Aldehyde—>chlb
Tail
> hydrophobic
>phytol tail
Lipid Head- chlorophyll Head
Lipid tail - chlorophyll tail
Absorption spectrum of
Chla
Chlb
Carotenoid
Action spectrum
Measure in terms of
Action spectrum & Absorption spectrum overlap
Chla
Max photosyn at 430nm &662nm
Chlb
Max photosyn at 450nm &640nm
Carotenoids
450-550 [ LEAST EFFECTIVE IN PHOTOSYN]
Action spectrum
> o2 evolution
Blue & red
ABSORPTION SPECTRUM OF CHLA
(Blue and red light absorbed the most)
& ACTION SPECTRUM
(Photosynthesis most by Blue and red)
Not completely overlap cuz light also absorbed by chlb &Carotenoid involved in photosynthesis
PHOTOSYSTEM PS1 & PS2
1.Named based on ________
2. Thylakoid contains
3. Ps1
>wavelength absorbed
>energy absorbed
> RC
>LHC-1
Constitutes
Function
4.PS2
>wavelength absorbed
>energy absorbed
> RC
>LHC-2
Constitutes
Function
5. IN granal THYLAKOID
6. IN STROMAl thylakoid /stromal lamella
7. rxn coverting co2 to glucose
8. rxn converting h2o to o2
1.order of Discovery
2. PS2 & PS1
3.
>700nm
> Lambda high energy low»_space;
Electron of chla not excited
>Reaction center chla single molecule
>light harvesting complex -1
— protein
—-Light harvesting pigment 1
Contains antennae molecules
Like Carotene + Xanthophyll +chlb
Absorbed shorter wavelength
Hence energy higher
Therefore provide energy to main RC to excite 2electron
- Ps2
>680nm
> Lambda high energy low»_space;
Electron of chla not excited
>Reaction center chla single molecule
>light harvesting complex -2
— protein
—-Light harvesting pigment 2
Contains antennae molecules
Like Carotene + Xanthophyll +chlb
Absorbed shorter wavelength
Hence energy higher
Therefore provide energy to main RC to excite 2electron - Both ps1 & ps2
- Only ps1
7.dark rxn
8.light rxn
Light / photochemical rxn
1.Site
2.synthesis
3. Shield pigment
4. Important steps + location
1.Grana»thylakoid»_space;ps1 ps2
2.atp nadph
3. Carotenoids are shield pigs which absorb excess heat during light rxn to protect main chla from destruction
4. Photolysis of h20
Photo phosphorylation
>noncyclic»_space; grana
>cyclic»_space; stroma
Non cyclic photophosphorylation
1.Deficiency in ps2 satisfied by
2.Deficiency in ps1 satisfied by
3. energy formation
4.aka
1.Ps2[ inner thylakoid mem]
chla absorbs 680nm
2 photon absorbed ——>2e excited
[With help of antennae ]
——————uphill———
low redox to high redox potential
- PHEOPHYTIN [outer thylakoid mem]
1°acceptor of e
Chlorophyll without Mg - Plastoquinone PQ
Become PQ‐² takes 2H+ from stroma
PQH2 plastoquinol [2h+ given to lumen] - Cytochrome b6F
- Plastocyanin [PC]
———-downhill [2-6]——ETC ——
- Ps1
Absorbs 700nm
2photon absorbed —>2e excited
——–uphill———
- Fes [outer mem]
- Fd ferredoxin[outer mem]
——in presence of FNR———-
Ferredoxin NADP+ reductase Enzyme
9.NADP+[ outer mem]
2e + [2H+(stroma)] + [NADP+]
—–> NADPH + [H+]
final acceptor
- deficiency in ps2 satisfies by EXTERNAL DONOR h20
photolysis —> 2h+ and o2 added to lumen
2.satisfied by ps2 electrons - atp formed but ETC
nadph formed - z scheme
cyclic photophosphorylation
- reason
- energy formation
1.PS1
absorbs 700nm
2photon—–> 2 electron
2.Fes
1* acceptor
- plastoquinone
- cytochrome b6f
- plastocyanin
back to ps1 (final acceptor)
- electron never goes to nadp+ cuz fnr not there in stroma lamella
- atp formed due to ETC
nadp not formed
chemiosmotic hypothesis
1.given by
2. atp formation due to_______ across ______
3. H+ in lumen due to
conc in lumen_____ and conc in stroma_____
4. break proton gradient
>direction and transport
>complex
> cause of atp synthesws
- peter mitcheli
- proton gradient ,thylakoid membrane
- CONC IN LUMEN HIGH low in stroma
-photolysis
-plastoquinone (photon pump)
removed from stroma to lumen
- NADP+ removes proton from stroma
4.
> proton from lumen to stroma
along conc gradient
passive / downhill
facilitated diffusion(thru complex)
>atp synthase(enzyme)
cf—- coupling factor
- CF0
integral protein
embedded in membrane
-CF1
peripheral protein
(towards stroma)
> due to movement of proton change in conformation / structure of CF1 which lead to formation of ATP { PHOTOPHOSPHORYLATION}
ASSIMILATORY POWER OF LIGHT RXN
18 ATP
12 NADPH
DARK REACTION
1. site
2.product
3. no.of co2 fixed
4. energy req for fixation
5. types
1.stroma
2.GLUCOSE
3.6
4.
1»_space;> 3atp 2 nadp
6»>18atp 12nadp
5.
c3 or calvin cycle
c4 or hatch and slack
