Tag: biological oxidation

Questions Related to biological oxidation

FAD is electron acceptor in citric acid cycle during the oxidation of

bio-chemistry biological oxidation oxidative phosphorylation living organisms and energy production glycolysis

  1. Malic acid to oxaloacetatic acid.

  2. Succinic acid to malic acid.

  3. Citric acid to -ketoglutaric acid.

  4. $\alpha$-ketoglutaric acid to succinic acid.

Show answer
Correct Option: B
Explanation:

The Krebs cycle is the condensation of acetyl group with oxaloacetic acid and water to yield citric acid and leads to the formation of Oxalo acetic acid.

Eighth step in which Succinic acid converts into Fumaric acid in the presence of enzyme succinic dehydrogenase release energy and form FADH which yields 2ATP.
So the correct option is 'Succinic acid to Fumaric acid.'

The process of phosphorylation takes place in

bio-chemistry biological oxidation oxidative phosphorylation living organisms and energy production glycolysis

  1. Glycolysis

  2. Kreb's cycle

  3. HMP pathway

  4. All of the above

Show answer
Correct Option: D
Explanation:

Phosphorylation is the addition of a phosphate (PO$ _{4}^{3-}$) group to a protein or other organic molecule. Phosphorylation results in the formation of ATP, which is the energy currency of cell. Phosphorylation occurs as a part of glycolysis, Kreb's cycle and HMP pathway.

Oxidative phosphorylation occurs during the process of

bio-chemistry biological oxidation oxidative phosphorylation living organisms and energy production glycolysis

  1. Protein synthesis

  2. $N _{2}$ fixation

  3. Respiration

  4. Transpiration

Show answer
Correct Option: C
Explanation:

Oxidative phosphorylation is a metabolic process, which is a part of respiration, which occurs in mitochondria. As a result of this process energy is released in the form of ATP.

In oxidative phosphorylation, oxidation and phosphorylation take place simultaneously and forms:

bio-chemistry biological oxidation oxidative phosphorylation living organisms and energy production glycolysis

  1. NADP

  2. DPN

  3. Pyruvic acid

  4. ATP

  5. Both B and D

Show answer
Correct Option: E
Explanation:

Oxidative phosphorylation refers to synthesis of ATP by ADP and Pi driven by energy released from oxidation of reducing powers NADH and FADH2 by transfer of their electrons through electron trasnport chain to oxygen. Electron trasnport chain is present in inner mitochondrial membrane and passes the electrons down a series of carriers and pump protons into the intermembrane space. Oxygen serves as final electron acceptor in oxidation of NADH and FADH2 and the resulting proton gradient serves as energy source for the enzyme ATP synthase to synthesize ATP. So final products of oxidative phosphorylation are ATP, NAD and FAD. DPN (diphosphopyridine nucleotide), also called as NAD. Correct answers are D and B. NADP is coenzyme of photosynthetic light reactions. Puruvic acid is product of glycolysis. 

Oxidative phosphorylation is the formation of 

bio-chemistry biological oxidation oxidative phosphorylation living organisms and energy production glycolysis

  1. NADPH$ _{2}$ in respiration

  2. ATP in respiration

  3. NADPH$ _{2}$ in photosynthesis

  4. ATP in photosynthesis

Show answer
Correct Option: B
Explanation:

Oxidative phosphorylation is the metabolic pathway in which the mitochondria in cells use their structure, enzymes and energy released by the oxidation of nutrients to reform ATP in respiration.

Biological phosphorylation is the formation of 

bio-chemistry biological oxidation oxidative phosphorylation living organisms and energy production glycolysis

  1. $N _{2}$

  2. $CO _{2}$

  3. $ATP$

  4. $SO _{2}$

Show answer
Correct Option: C
Explanation:

Biological phosphorylation is of two types- protein phosphorylation and oxidative phosphorylation. In protein phosphorylation, the proteins get attached with a phosphate group. Oxidative phosphorylation is the metabolic pathway in which the mitochondria in cells use their structure, enzymes, and energy released by the oxidation of nutrients to reform ATP.

$FAD^+$ is reduced during conversion of 

bio-chemistry biological oxidation oxidative phosphorylation living organisms and energy production glycolysis

  1. Citric acid to isocitric acid

  2. Isocitric acid to $ \alpha - $ ketoglutaric acid

  3. $ \alpha - $ ketoglutaric acid to succinyl CoA

  4. Succinic acid to fumaric acid

Show answer
Correct Option: D
Explanation:

During one of the steps of Krebs cycle, succinic acid is converted to fumaric acid. The reaction is accompanied by coenzyme FAD (flavin adenine nucleotide). This oxidation reaction liberates less free energy as compared to other oxidation reactions. FAD$^+$ is the hydrogen acceptor in this reaction as there is very less free-energy change. In this reaction, succinic acid is oxidized to fumaric acid. At the same time, FAD$^+$ is reduced to FADH$ _2$. 

Thus, the correct answer is option D.

During aerobic respiration, the substrate level phosphorylation takes place in.

bio-chemistry biological oxidation oxidative phosphorylation living organisms and energy production glycolysis

  1. Cytoplasm only

  2. Mitochondria only

  3. Cytoplasm and mitochondria

  4. Cytoplasm and Golgi complex

Show answer
Correct Option: A


Within the mitochondrion, the proton gradient develops across the

bio-chemistry biological oxidation oxidative phosphorylation living organisms and energy production glycolysis

  1. Outer membrane

  2. Inner membrane

  3. Intermembrane space

  4. Matrix

Show answer
Correct Option: B
Explanation:

The electrons from NADH AND FADH$ _2$ flows through the inner mitochondrial membrane, thus forming a proton gradient i.e; building an H+ pump which flows through the membrane enzyme complex. An enzyme responsible for this process and energy generation is ATP synthase.

So, the correct option is ' inner membrane'.

Choose the correct answers from the alternatives given :
Chemiosmotic phosphorylation is dependent upon

bio-chemistry biological oxidation oxidative phosphorylation living organisms and energy production glycolysis

  1. the ability of ADP? to join with P even in the absence of a supply of energy

  2. the establishment of an electrochemical hydrogen ion $(H^+)$ gradient

  3. an outside supply of phosphate and other chemicals

  4. the diffusion of waste across a differentially permeable membrane

Show answer
Correct Option: B
Explanation:

  • Chemiosmotic phosphorylation is the process where ATP is formed by the ATP synthase complex which is present in the inner membrane of the mitochondria.
  • The formation of ATP by this complex takes place when 2 hydronium ions are transported across the complex from the inter membrane space down its concentration gradient.
  • Thus the formation of ATP in this process takes place due to the concentration gradient that is formed by the presence of hydronium ion that is formed by the ETS Chain when the electron along with hydronium ions are transported from the NADH and FADH.
  • Therefore the answer 'the establishment of an electrochemical hydrogen ion (H+) gradient' is correct.