XI: Chapter 13- Photosynthesis Flashcards
C₅₅H₇₂O₅N₄Mg is the molecular formula of
Chlorophyll a
C55H74O6N4Mg is the molecular formula of
Chlorophyll b
C35H32O5N4 is the molecular formula of
Chlorophyll c
C54H70O6N4Mg is the molecular formula of
Chlorophyll d
How many pyrrole rings are present in a chlorophyll molecule?
4
What forms the head of chlorophyll molecule?
Porphyrin ring (tetrapyrrole structure)
What forms the tail of chlorophyll molecule?
Phytol tail
Phytol tail is absent in which chlorophyll?
Chlorophyll c
Carotenol is the other name for
Xanthophyll
Name the basic carotene.
Lycopene
What makes tomato, rose, etc red?
Lycopene (carotene)
What gives colour to the autumn foliage?
Leutin (xanthophyll)
Where are carotenols found in animals?
Corpus luteum
What happens to carotenes in animals?
It is converted into vitamin A
What is the colour of allophycocyanin?
Green
Which are the universal pigments found in plant kingdom?
Chlorophyll a, β-Carotene
Which wavelength of light does photosystem I absorb the most?
700 nm
Which wavelength of light does photosystem II absorb the most?
680 nm
Which photosystem is light green in colour?
Photosystem I
Which photosystem is dark green in colour?
PSII
How many chlorophyll a molecules does PSI have?
200-400
How many chlorophyll a molecules does PSII have?
200
Where is PS I found?
Stroma lamellae and granum
Where is PSII found?
Granum
Which photosystem is involved in both cyclic and noncyclic photophosphorylation?
PSI
What is the light harvesting complex made of in a photosystem?
Pigment molecules and proteins
What forms the antenna of the photosystem?
Light harvesting complex
What is present in the reaction centre of a photosystem?
Chlorophyll a
In which phase of photosynthesis are assimilatory powers generated?
Light reaction
Hill reaction in photosynthesis is also called
Light reaction
What occurs in the photophysical phase of light reaction?
Accessory pigments transfer light energy to chlorophyll a
Chlorophyll a is activated by photons
What happens in the photochemical phase of light reactions?
Photolysis of water, production of assimilatory powers
How much energy does the electron liberated from photosystem by a photon contain?
23 kcal/mol
How many ATP and NADPH molecules are produced in cyclic photophosphorylation?
2 ATP and no NADPH
What is the effect of photosynthetic poisons on cyclic photophosphorylation?
No effect
What is the sequence of electron transport chain in cyclic photophosphorylation?
PSI X FeS Fd PQ Cyt-b6 Cyt-f PC PSI
How many ATP and NADPH molecules are produced in non-cyclic photophosphorylation?
1 ATP, 1 NADPH
Which is the first electron donor in non cyclic photophosphorylation?
Water
What is the sequence of electron transport chain in non-cyclic photophosphorylation?
PSII Phe PQ Cyt-b6 Cyt-f PC PSI FeS Fd
What is also called Blackman’s reaction?
Dark reaction of photosynthesis
Which is the first stable product formed from combination of ribulose 1,5 bisphosphate with carbon dioxide?
3-phoshoglycerate
How many ATP and NADPH are utilized in calvin cycle?
3 ATP and 2 NADPH
Which algae were used by Calvin to formulate the calvin cycle?
Chlorella and Scendesmus
C3 cycle is found in which monocots?
Wheat and rice
What kind of inhibition is seen when oxygen reacts with RuBisCO instead of CO2?
Competitive inhibition
Which photosynthetic pathway is found in Euphorbia?
C4 cycle
In what manner are bundle sheath cell and mesophyll cells arranged in C4 plants?
Crown ring manner
In what form is oxaloacetic acid transfered from mesophyll cell to bundlesheath cell in C4 plants?
Malic acid
What is formed from the breakdown of malic acid in bundle sheath cell in C4 plants?
Pyruvic acid and CO2
In which type of plants is CAM pathway found?
Succulent xerophytes
Which type of photosynthetic pathway is found in pineapples?
CAM pathway
Which is the first stable product of CAM pathway?
Oxaloacetic acid
Where is malic acid stored during ngiht in CAM plants?
Vacuole
Which is the first CO2 acceptor in CAM plants?
Phosphoenol pyruvate
Which is the first stable product formed during photorespiration?
2-phosphoglycolate
During photorespiration, glycolate from mitochondria transfers to which organelle?
Peroxisomes
Glyoxylate forms which compound during photorespiration?
Glycine
How many nitrogen are lost for conversion of glycine to serine?
1
How many NADH are formed during the conversion of glycine to serine in photorespiration?
1
Blackman’s law of limiting factors is a modification of
LIebeg’s law of minimum
How is photosynthesis affected when CO2 concentration increase by 0.05%
Photosynthesis increases
In which light is photorespiration maximum?
Red light
How is photosynthesis affected when plant is subjected to intermittent light?
No photosynthesis occurs
What is the decreasing effect of high light intensity on photosynthesis called?
Solarisation
What is the decreasing effect of high concentration of oxygen on photosynthesis in C3 plants called?
Warburg’s effect
What is the effect of high concentration of oxygen on C4 plants?
No effect
What is photosynthetic number?
The amount of CO2 absorbed in grams by 1 gram chlorophyll.
Where do the hydrogen ions accumulate according to the chemiosmotic hypothesis?
In the lumen of thylakoid
Who proved that green plants produce food using their leaves?
Stephen Hals
Who reported that plant purify air?
Priestley
Who reported that plants only produce food in the presence of light?
Jan ingenhouz
Who gave the concept of cardinal points?
Julius van Sachs
Who stated that the first stable product of photosynthesis is starch?
Julius van Sachs
Who gave the first action spectrum of photosynthesis?
Englemann
Which alga did Englemann use to give his action spectrum?
Cladophora
Who recognised CO2 as the impure air?
Lavosier
Who gave the concept of two photosystems?
Arnold and Emerson
Who proved that the oxygen produced in photosynthesis is liberated from water?
van Neil
What is the sharp reduction in photosynthesis when monochromatic beam of wavelength greater than 680nm is used called?
Red drop
Who reported the red drop effect for the first time?
Emerson
What is the enchancement effect?
Increase in photosynthesis when two monochromatic beams of different wavelength are used together.
What does the enhancement effect in plants prove?
Existence of two photosystems.
Who discovered that green parts of plants release oxygen?
Jan Ingenhousz
Who first discovered chlorophyll in plants?
Julius von Sachs
How do the chloroplasts arrange themselves in a mesophyll cell?
Along the walls
What is the colour of chlorophyll a?
Blue-green
What is the colour of chlorophyll b?
Yellow green
Why are no NADPH formed in cyclic photophosphorylation?
CYclic photophosphorylation occurs inside stroma lamella where NADP reductase enzymes are missing,
Where are protons transported as electrons move through the photosystems?
Across the membrane into the lumen
Where is the primary acceptor of electrons located according to chemiosmotic hyptothesis?
Towards the outer side of the membrane
What are the parts of ATP synthase enzyme?
CF0- embedded in the thylakoid membrane
Cf1- faces stroma
What kind of transport occurs in chemiosmotic synthesis?
Facililtated diffusion
How did Melvin Calvin discover that the first CO2 fixation product was a 3 carbon organic acid?
Using radioactive techniques
Which is the most crucial step of the calvin cycle?
Carboxylation
Bundle sheath cells have very thin walls. True/false?
False. They have very thick walls.
What does RuBisCO have greater affinity for- CO2 or O2?
CO2
Which plants shows greater tolerance to higher temperatures- C3 or C4?
C4
What kind of relationship do incident light and CO2 fixation rates have at low light intensities?
Linear relationship
At what percentage of full sunlight does light saturation occur?
10%
Which plants show saturation of photosynthesis at lower concentration of CO2?
C4 plants
Out of light reactions and dark reactions in photosynthesis which is affected more by higher temperatures?
Dark reaction
