Photosynthesis

Question 1

Two processes in the photosynthesis

Answer 1

Light dependent and carbon fixation cycle

Question 2

Two types of photosynthetic organisms

Answer 2

Oxygenic that produces oxygen and anoxygenic that don’t produce oxygen

Question 3

Products of light reaction

Answer 3

ATP and NADPH

Question 4

Anoxygenic organism uses what other pathway than carbon fixation

Answer 4

Reductive tricarboxylic acid cycle and hydroxypropionate pathway

Question 5

Three photosynthetic pigments

Answer 5

Chlorophyll, carotenoids, and phycobilin

Question 6

Are chlorophyll lipid soluble?

Answer 6

Yes

Question 7

Types of chlorophyll molecules?

Answer 7

Chla, b, c, and d

Question 8

Chlorophyll made of?

Answer 8

Chlorin and porphyrin

Question 9

Chlorin has?

Answer 9

Three pyrolle rings and one pyrolline ring. One cyclopentanone ring and an isoprene tail

Question 10

Porphyrin has

Answer 10

Four pyrrole rings.

Question 11

In chlorophyll magnesium is bound to how many nitrogen and by which bond?

Answer 11

Two nitrogen by covalent bonds

Question 12

Carotenoids

Answer 12

Long chain hydrocarbon having different isoprene residue in every molecule

Question 13

Carotenoids are subdivided into?

Answer 13

Carotene and xanthophyll

Question 14

Which one has oxygen, carotene or xanthophyll

Answer 14

Xanthophyll

Question 15

Role of carotenoids

Answer 15

Acts as a scavenger and quencher. Protects from oxidative damage. By taking electrons from excited chlorophyll molecules and dissipating into heat.

Question 16

What is photo inhibition

Answer 16

When an excited molecule reacts with oxygen it forms a singlet oxygen that is a reactive oxygen species

Question 17

Phycobilin structure

Answer 17

Noncyclic, linear tetrapyrrole. Structurally similar to bilirubins.

Question 18

Three types of phycobilin are?

Answer 18

Phycoerythrobilin, phycocyanobilin and allophycocyanobilin

Question 19

What protein does phycobilin produce

Answer 19

Phycobiliproteins

Question 20

Name the phycobiliproteins

Answer 20

Phycoerythin and phycocyanins.

Question 21

Who has phycobilin?

Answer 21

Brown algae and cyanobacteria

Question 22

Green photosynthetic bacteria has what photosynthetic pigment?

Answer 22

Chlorosome and plasma membrane

Question 23

Purple photosynthetic bacteria has what photosynthetic pigment?

Answer 23

Chromatophore of plasma membrane

Question 24

Absorption spectra

Answer 24

Degree of absorption by a molecule at different wavelengths

Question 25

Action spectra

Answer 25

Different wavelengths affecting photochemical reaction

Question 26

Photosynthetic unit? Discovered by?

Answer 26

A group of chlorophyll molecules that helps in producing one oxygen molecule. Discovered by Emerson and Arnold

Question 27

What did hill reaction tell

Answer 27

That O2 is obtained from oxidation of H2O not CO2

Question 28

What is the Hill Reagent? Why did he use it?

Answer 28

Hill reagent is Dichlorophenolindolphenol (DCPIP). He used it as an electron acceptor.

Question 29

Quantum yield

Answer 29

It is the number of oxygen made from one photon

Question 30

Quantum requirement

Answer 30

It is the number of photons used to make one oxygen.

Question 31

Two components of photosystem

Answer 31

Photochemical reaction centre and antenna molecules

Question 32

Two types of centre in photochemical reaction centre

Answer 32

Fe-S centre and pheophytin-quinone centre.

Question 33

Which bacteria does not have an antenna complex

Answer 33

Helicobacter

Question 34

Electron path in PS2

Answer 34

From P680* electron moves to pheophytin to plastoquinone to plastoquinol to cytb6f to plastocyanin and then to P700

Question 35

In PS2, the core antenna and peripheral antenna contains what?

Answer 35

Core antenna - CD47 and CD43 Peripheral antenna - LHC2

Question 36

In PS1 the peripheral and core antenna has which protein?

Answer 36

LHC1

Question 37

What is the main ion in the oxygen evolving complex

Answer 37

Mn2+

Question 38

Electron transfer in PS1

Answer 38

From P700* to modified chlorophyll molecules to phylloquinone to Fe-S complex to FD to FNR and then converts to NADPH

Question 39

One molecule of CO2 forms how many G3P?

Answer 39

2 G3P

Question 40

How many electrons are needed to form one NADPH

Answer 40

2e

Question 41

How is ATP formed during this e transfer

Answer 41

The energy that is released while transporting the electrons is used to transport protons in the lumen. Then these protons are transported out of the lumen which forms ATP. 3 photons = 1 ATP

Question 42

What forms during cyclic e flow? Is it beneficial?

Answer 42

Cyclic electron flow forms only ATP. It is preferred over non cyclic

Question 43

Function of protein kinase?

Answer 43

Disassociates the LHC2 from from PS2 to PS1 for the e transfer to PS1

Question 44

How many photons and protons used in cyclic e flow

Answer 44

4 photons and 8 protons