Tag: living organisms and energy production

Questions Related to living organisms and energy production

ATP formation in chloroplast and mitochondrion is explained by

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

  1. Cholodny-Went model

  2. Chemi-osmotic theory of Mitchell

  3. Munch's mass flow theory

  4. Relay pump theory of Godlewski

Show answer
Correct Option: B
Explanation:
A theory postulated by the biochemist Peter Mitchell in 1961 to describe ATP synthesis by way of a proton electrochemical coupling.
it is based on the proton gradient and transfer of an electron from the mitochondrial matrix in respiration or in the stroma with the photophosphorylation of photosystems forms ATP.
So the correct option is 'Chemi-osmotic theory of Mitchell'.

Chemiosmosis was first described by

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

  1. Boyer

  2. Walker

  3. Mitchell

  4. Meischer

Show answer
Correct Option: C
Explanation:

The chemiosmotic hypothesis of ATP synthesis in chloroplasts is based on proton gradient. The chemiosmotic hypothesis was explained by P. Mitchell in 1961. He recieved noble prize for it in 1978. ATP synthesis is linked to the development of a proton gradient across the membrane of the thylakoid of chloroplast and proton accumulation is towards the inside of the membrane i.e. in the lumen. 

When cell converts light energy into chemical energy, which of the following reaction would take place?

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

  1. ADP + iP = ATP

  2. ATP - iP = ADP

  3. AMP + iP = ADP

  4. GDP + iP = GTP

Show answer
Correct Option: A
Explanation:

Cells convert light energy is converted into chemical energy. During this process, a phosphate is added to adenosine diphosphate molecule to cause the formation of ATP.

So the correct option is 'ADP + iP = ATP'.

Oxidative phosphorylation refers to

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

  1. Anaerobic production of ATP

  2. The citric acid cycle production of ATP

  3. Production of ATP by chemiosmosis

  4. Alcoholic fermentation

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Correct Option: C

ATP synthesis in cell requires

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

  1. $H^+$ gradient across the membrane

  2. $K^+$ gradient across the membrane

  3. $PO^{3-} _4$ gradient across the membrane

  4. $Ca^{2+}$ gradient across the membrane

Show answer
Correct Option: A
Explanation:
A) A ${ H }^{ + }$ gradient or proton pump is developed in the lumen of the thylakoid which helps in ATP synthesis.
B) ${ K }^{ + }$ does not play a role in ATP synthesis.
C) ${ PO } _{ 4 }^{ 3- }$ does not play a role in ATP synthesis.
D) ${ Ca }^{ 2+ }$ is involved in the photolysis of water.
So the correct answer is '${ H }^{ + }$ gradient across the membrane'.

ATP was discovered by 

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

  1. Blackman

  2. Bowman

  3. Lipmann

  4. Karl Lohmann

Show answer
Correct Option: D
Explanation:

ATP was discovered by Karl Lohman. ATP is the energy currency of our cell. It is formed as a result of phosphorylation.

The chemiosmotic coupling hypothesis of oxidative phospohorylation proposes that adenosine triphosphate is formed because

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

  1. A Proton gradient forms across the inner membrane

  2. There is a change in the permeability of the inner mitochondria membrane toward adenosine diphosphate

  3. High energy bonds are formed in mitochondrial proteins

  4. ADP is pumped out of the matrix into the intermembrane space

Show answer
Correct Option: A

Chemiosmotic mechanism of ATP synthesis was proposed by 

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

  1. Warburg

  2. Dickens

  3. Krebs

  4. P. Mitchell

Show answer
Correct Option: D
Explanation:

Chemiosmosis is the movement of ions across a selectively permeable membrane, down their electrochemical gradient. More specifically, it relates to the generation of ATP by the movement of hydrogen ions across a membrane during cellular respiration or photosynthesis. Peter D. Mitchell proposed the chemisomotic hypothesis in 1961. The theory suggests essentially that most ATP synthesis in respiring cells  comes from the electrochemical gradient across the inner membranes of mitochondria by using the energy of $NADH _2$ and $FADH _2$ formed from the breaking down of energy-rich molecules such as glucose.

Chemiosmotic theory of ATP synthesis in the chloroplasts and mitochondria is based on

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

  1. Membrane potential

  2. Accumulation of K ions

  3. Proton gradient

  4. Accumulation of Na ions

Show answer
Correct Option: C

With reference to photosynthesis, what is the $CF _0$ - $CF _1$ complex?

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

  1. ATP synthetase

  2. Ferredoxin-NADP reductase

  3. Cytochrome $b6$/f complex

  4. RuBP carboxylase

Show answer
Correct Option: A