Tag: mechanism of photosynthesis

Questions Related to mechanism of photosynthesis

Who am I?

bio-chemistry biological oxidation chemiosmotic hypothesis living organisms and energy production mechanism of photosynthesis

  1. I am ATP producing factory

  2. I am single layered, but maintain cellular osmotic pressure

  3. I support the cell, but I am not cell wall I have a body resembling net

  4. I am chemical factory of the cell

  5. Leaves are green because of me

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Correct Option: A

How many ATP molecules will be produced when one molecule of 3-phosphosphoglyceric acid is completely oxidised : 

bio-chemistry biological oxidation chemiosmotic hypothesis living organisms and energy production mechanism of photosynthesis

  1. 16

  2. 32

  3. 64

  4. 48

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Correct Option: A

How many ATP molecules are produced after complete oxidation of one molecule of fructose-1, 6-bis-phosphate ?

bio-chemistry biological oxidation chemiosmotic hypothesis living organisms and energy production mechanism of photosynthesis

  1. 40

  2. 32

  3. 38

  4. 44

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Correct Option: A

During photosynthesis 

bio-chemistry biological oxidation chemiosmotic hypothesis living organisms and energy production mechanism of photosynthesis

  1. $O _{2}$ evolved comes from $CO _{2}$

  2. ATP is formed

  3. ATP is not formed

  4. Water is required as medium but it does not take part in photosynthesis

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Correct Option: B
Explanation:

Photosynthesis is an anabolic process, which helps in forming ATP, where it is called as energy currency. During the light reaction photophosphorylation takes place producing ATP and $NADPH _2$ which is used as energy source for dark reaction.

ATP synthesis proposed by Peter Mitchell is 

bio-chemistry biological oxidation chemiosmotic hypothesis living organisms and energy production mechanism of photosynthesis

  1. Phosphorylation

  2. Photophosphorylation

  3. Oxidative phosphorylation

  4. Chemiosmotic synthesis

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Correct Option: D
Explanation:

Peter Mitchell proposed a theory to explain the production of ATP which is 'Mitchell's chemiosmotic coupling hypothesis'. According to this theory:

  1. Inner membrane of mitochondria acts as a transducer of energy and converts energy to chemical energy of ATP along the electrochemical gradient.
  2. Inner mitochondrial membrane is impermeable to NADH, ATP, H+, OH-.
  3. ATP synthesis and electron transport are coupled with proton gradient.
So the answer is 'Chemiosmotic synthesis'.

Energy required to synthesise ATP from ADP and inorganic phosphate is

bio-chemistry biological oxidation chemiosmotic hypothesis living organisms and energy production mechanism of photosynthesis

  1. 2500 cal

  2. 7600 cal

  3. 12000 cal

  4. 20000 cal

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Correct Option: B

ATP is injected in cyanide poisoning because it is

bio-chemistry biological oxidation chemiosmotic hypothesis living organisms and energy production mechanism of photosynthesis

  1. Necessary for cellular functions

  2. Necessary for $Na^+$ - $K^+$ pump

  3. $Na^+$ - $K^+$ pump operates at the cell membranes

  4. ATP breaks down cyanide

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Correct Option: A

Chemiosmotic hypothesis given by Peter Mitchell proposes the mechanism of

bio-chemistry biological oxidation chemiosmotic hypothesis living organisms and energy production mechanism of photosynthesis

  1. Synthesis of ATP.

  2. Synthesis of FADH$ _2$.

  3. Synthesis of NADH.

  4. Synthesis of NADPH.

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Correct Option: A
Explanation:

Peter Mitchell proposed a hypothesis known as the chemiosmotic hypothesis that an electrochemical concentration gradient of protons across a membrane could be utilized to make ATP. He linked this process to osmosis, the diffusion of water across a membrane, this is the reason it is called chemiosmosis.

So the correct option is 'Synthesis of ATP'.

Light reaction in stroma lamellae of chloroplast results in the production of

bio-chemistry biological oxidation chemiosmotic hypothesis living organisms and energy production mechanism of photosynthesis

  1. ATP

  2. NADPH$ _2$

  3. ATP + NADPH$ _2$

  4. O$ _2$

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Correct Option: C
Explanation:

A) Along with ATP, ${ NADPH } _{ 2 }$ is also produced.
B) Along with ${ NADPH } _{ 2 }$, ATP is also produced.

C) The light reaction that takes place in the stroma lamellae is the non-cyclic phosphorylation and ATP and ${ NADPH } _{ 2 }$ are the products.
D) Oxygen is also liberated during the light reaction but is not the main product.
So the correct answer is 'ATP + ${ NADPH } _{ 2 }$'.

ATP does not provide phosphate in the reaction

bio-chemistry biological oxidation chemiosmotic hypothesis living organisms and energy production mechanism of photosynthesis

  1. Glucose Glucose 6-P

  2. Fructose Fructose 6-P

  3. PGAL 1 : 3-diPGA

  4. PEPA Pyruvic acid

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Correct Option: C