Photosynthesis in higher plants

Question 1

What type of process is photosynthesis?

Answer 1

Physio-chemical process

Question 2

What is EnAnRe?

Answer 2

energy is used (endergonic)
constructive process ( anabolic)
reduction of co2 (reductive)

Question 3

Uses of photosynthesis?

Answer 3

1. primary source of food for all organisms
2. responsible for evolution of o2 for survival

Question 4

What does Moll’s half leaf experiment prove?

Answer 4

It proves that co2 is essential for photosynthesis

Question 5

Timeline of Joseph priestly

Answer 5

1733-1804

Question 6

When did priestly start his experiments and when did he discover o2?

Answer 6

1770
1774

Question 7

What did priestly state?

Answer 7

He stated that plants restore to air what breathing mouse and burning candle removed

Question 8

what did priestly’s experiment use?

Answer 8

Bell jar + mouse + burning candle + mint plant

Question 9

Time line of Jan ingenhouz

Answer 9

1730-1799

Question 10

Statement of ingenhouz

Answer 10

Stated that green parts release o2 in the presence of sunlight

Question 11

What experiment did ingenhouz do?

Answer 11

He repeated the experiment of priestly in dark and sunlight.
in sunlight the results were true but in dark the animal died and candle extinguised.
he introduced hydrilla plant and noticed the formation of bubbles, on testing they were found to be o2

Question 12

When did julius von sachs conduct his experiment?

Answer 12

1854

Question 13

What is sachs discover?

Answer 13

He provided evidence that there is production of glucose when plants grow. later it is stored as starch

Question 14

Timeline of T.W Engelmann

Answer 14

1843-1909

Question 15

What did engelmann work on?

Answer 15

He worked on green algae cladophora in suspension of aerobic bacteria.

Question 16

What were aerobic bacteria used to detect?

Answer 16

Site of o2 evolution

Question 17

What did engelmann observe?
What did he provide?

Answer 17

He observed that aerobic bacteria accumulated in blue and red regions of spectrum.
He provided first action spectrum which roughly resembled absorption spectrum of chl a and b.
He gave the first empirical equation of photosynthesis.
Co2 + H20 ———> CH2O + O2

Question 18

TimeLine of cornelius von neil

Answer 18

1897-1985

Question 19

What did von neil work on?
What did he infer?

Answer 19

He worked on green sulphur bacteria and purple sulphur bacteria.
He infered that O2 evolved dudring photosynthesis is from H2) not from CO2.

Question 20

Who used radio isotopic technique to prove von neil’s statement?

Answer 20

Ruben and Kamen

Question 21

Range of visible light and PAR

Answer 21

390-760nm
400-700nm

Question 22

Why are chloroplast aligned close to cell walls?

Answer 22

1. diffusion of gases
2. get optimum sunlight

Question 23

How are chloroplast placed at high and low light intensities?

Answer 23

flat surface of chloroplast is parallel to cell wall at low light intensities
flat surface of chloroplast is perpendicular to cell wall at high light intensities.

Question 24

Where do light reaction occur?

Answer 24

Grana thylakoids and stoma lamellae

Question 25

Which pigments are grana thylakoids made of and what do they do?

Answer 25

Chlorophyll and carotenoids They capture sunlight and synthesize chemical intermediates call ATP & NADPH. They also synthesize O2 in atmosphere

Question 26

What are dark reactions also called as and why?

Answer 26

Carbon reactions as photosynthetic enzymes fix co2 into carbohydrates called glucose by incorporating chemical intermediates of light phase

Question 27

Where do dark reactions occur?

Answer 27

Stroma

Question 28

How are pigments separated?

Answer 28

Paper chromatography

Question 29

Give colour and chemical formula of 1. carotene 2. xanthophyll 3. chl a 4. chl b

Answer 29

1. C40H56, orange or red 2. C40H56O2, yellow 3. C55H72O5N4Mg, bright green or blue green 4. C55H70O6N4Mg, yellow green

Question 30

What are carotenoids? give its colour

Answer 30

Carotene + Xanthophyll Yellow orange

Question 31

Shape of chlorophyll

Answer 31

tadpole shaped

Question 32

Give types of chlorophyll and where they are present

Answer 32

Chl a - all plants and BGA Chl b - all green algae and higher plants Chl c - Brown algae, diatoms, dinoflagellates Chl d - red algae Chl e - Xanthophyceae

Question 33

4 corners of chlorophyll represent

Answer 33

4 pyrol rings

Question 34

Head of chlorophyll is called as it is the site of?

Answer 34

tetrapyrollic or prophyrin electron rearrangement

Question 35

What is present in middle of chlorophyll?

Answer 35

single central non ionic Mg atom

Question 36

Where is prophyrin also seen in?

Answer 36

Haemoglobin and cytochromes

Question 37

What is phytol ring?

Answer 37

20C alcohol attached within the lipid of membrane

Question 38

Main pigment involved in photosynthesis?

Answer 38

Chl a

Question 39

function of chl b, carotenes, xanthophyll

Answer 39

capture wider wavelengths of light and pass the energy to chl a for efficient photosynthesis

Question 40

What are carotenoids also called as? what do they do?

Answer 40

Shield pigments They protect the plant from photo oxidation and excess heat

Question 41

What is absorption spectrum

Answer 41

Graphic curve representing the amount of energy of different wavelengths of light absorbed by pigments

Question 42

What is action spectrum

Answer 42

Graphic curve showing rate of photosynthesis at different wavelengths of light absorbed by pigments

Question 43

Pigments organize into?

Answer 43

Discrete light harvesting complex

Question 44

LHC is a part of? what does this part include? how are they arranged?

Answer 44

Photosystem PS1 and PS2 named in order of discovery not in terms of function

Question 45

Give reaction centre of PS1 and PS2

Answer 45

PS1 - chl a can absorb max of 700nm PS2 - chl a can absorb max of 680nm

Question 46

where does splitting of h2o take place in chemiosmotic cycle

Answer 46

inner side of membrane or lumen

Question 47

chemiosmosis process requires

Answer 47

membrane,proton pump, proton gradient, ATP synthetase

Question 48

Who used the term assimilatory power

Answer 48

arnon

Question 49

NADPH alone is called ______power

Answer 49

reducing

Question 50

How many co2, atp and nadph are used to make 1 molecule of glucose in C3 cycle

Answer 50

6co2 18ATP 12NADPH

Question 51

C4 plants lack

Answer 51

photorespiration

Question 52

special anatomy of c4 leaves is called

Answer 52

kranz anatomy

Question 53

how many atp are consumed in C4

Answer 53

2atp

Question 54

loss of co2 occurs in ________ in photorespiration

Answer 54

mitochondria