Tag: bio-chemistry

Questions Related to bio-chemistry

Chemiosmosis refers to the view that an ion flowing down its electrochemical gradient drives ATP synthesis. The ion in question is?

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

  1. Phosphate

  2. Sodium

  3. Iron

  4. Hydrogen

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Correct Option: A

The energy-carrying compound in the living cell is ATP.

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

  1. True

  2. False

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Correct Option: A
Explanation:

ATP captures chemical energy obtained from the breakdown of food molecules and its hydrolysis (ATP to ADP + Pi or ADP to AMP + Pi) releases energy that can be used to drive various energy-requiring processes in cells. So, the correct option is 'True'.

Choose the correct answers from the alternatives given .
Energy coupling of endergonic and exergonic reactions within cells

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

  1. Permits biological reactions to proceed at temperatures consistent with life

  2. Uses heat released by one reaction to fuel the other reaction

  3. Utilizes ATP to carry energy between the exergonic and endergonic reactions

  4. All of the above

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Correct Option: D
Explanation:
Energy coupling is the use of an exergonic process to carry out an endergonic process. The energy released in an exergonic process is used to develop an endergonic process. The ATP is responsible for mediating the energy coupling of cells, it is the energy currency. It is used to boost many cellular reactions that require energy. This also provides the energy required for reactions without too much increase in temperature. 
So, the correct option is 'All of the above'.

Read the given statements and select the correct option. 
Statement 1 : In photosynthesis, during ATP synthesis, protons accumulate in the lumen of thylakoid.
Statement 2 : In respiration, during ATP synthesis, protons accumulate in the intermembrane space of mitochondria. 

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

  1. Both statement 1 and 2 are correct

  2. Statement 1 is correct but statement 2 is incorrect.

  3. Statement 1 is incorrect but statement 2 is correct

  4. Both statement 1 and 2 are incorrect

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Correct Option: A
Explanation:

Photolysishappens in the thylakoids, producing H+ ions inside the thylakoid membrane., a gradient of hydrogen ions will form across the membrane, ATP synthase take the advantage of this gradient, by allowing hydrogen ions to leak out of the membrane capturing their energy and phosphorylating ADP into ATP, while another statement is correct for mitochondria.

So, the correct option is 'Both statement 1 and 2 are correct'.

Select the correct option:

Study the following statements regarding chemiosmotic hypothesis in mitochondria and select the correct ones.
(i) ${F} _{1}$ headpiece contains the site for the syntesis of ATP from ADP+Pi.
(ii) ${F} _{0}$ part forms the channel through which protons cross the inner membrane.
(iii) For each ATP produced, ${2H}^{+}$ pass through ${F} _{0}$ from the intermembrane space to the matrix down the electrochemical proton gradient.

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

  1. (i) and (ii)

  2. (ii) and (iii)

  3. (i) and (iii)

  4. (i),(ii) and (iii)

Show answer
Correct Option: D
Explanation:

  In the given question, the correct statements are as follows:

(i) F1 headpiece contains the site for the synthesis of ATP from ADP+Pi.

(ii) F0 part forms the channel through which protons cross the inner membrane.

(iii) For each ATP produced, 2H+ pass through F0 from the intermembrane space to the matrix down the electrochemical proton gradient.

So, the correct answer is '(i),(ii) and (iii)'.


During chemiosmotic synthesis of ATP, protons diffuse through $CF {0}$ channels that activates ATPase enzyme. As a result, one molecule of ATP is formed when _______ passes through ATPase. 

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

  1. $4H^{+} $

  2. $H^{+} $

  3. $2H^{+} $

  4. $6H^{+} $

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Correct Option: C
Explanation:

During chemiosmotic synthesis of ATP, protons diffuse through CFo channels that activates ATPase enzyme. As a result, one molecule of Atp is formed when two hydrogen ions pass through ATPase.

So, the correct option is '$2H^+$.

Which one respiratory complex is coupled with ETS for ATP synthesis?

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

  1. Complex I

  2. Complex III

  3. Complex IV

  4. Complex V

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Correct Option: D
Explanation:

ATP synthase is also called complex V. It is the final enzyme in the oxidative phosphorylation pathway and utilizes the energy stored in a proton gradient across a membrane to drive the synthesis of ATP from ADP and phosphate (Pi).

So, the correct option is 'Complex V'.

Breakdown of proton gradient developed during chemiosmosis leads to a halt in the release of 
bio-chemistry biological oxidation chemiosmotic hypothesis living organisms and energy production mechanism of photosynthesis

  1. Oxygen

  2. electrons

  3. Energy

  4. Protons

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Correct Option: C
Explanation:

According to the chemiosmotic theory of Peter Mitchell, a proton gradient created by the ETS across the membrane leads to the passive movement of protons from the intermembrane space into the matrix or the stroma, through ATP synthase present on the inner membrane. The passive energy released by the protons is used for the synthesis of ATP from ADP. If a proton gradient breaksdown there will be no synthesis of ATP and no movement of protons across the membrane.

So, the correct answer is 'Energy'

Which of the following is an incorrect combination of organism with its chromosome number in mieocyte and in gamete?

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

  1. Onion, $24, 12$

  2. Ophioglossum, $1260, 630$

  3. Human beings, $46, 23$

  4. Fruit fly, $8, 4$

Show answer
Correct Option: A
Explanation:

Chromosome number in meiocyte $(2n)$ of onion cell is $32$, while chromosome number in gamete $(n)$ is $16$.

Which part of the plant takes in carbon dioxide from the air for photosynthesis.

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

  1. Root hari

  2. Stomata

  3. Leaf veins

  4. Sepals

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Correct Option: A