Tag: biological oxidation

Questions Related to biological oxidation

State whether the following statements are true or false .
The energy currency of a cell is adenosine triphosphate (ATP). ATP is chemically a lipoprotein.

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

  1. True

  2. False

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Correct Option: B
Explanation:
lipoprotein is a biomolecule that is a combination of fat and protein. While ATP is a nucleotide consisting of an adenine base attached to a ribose sugar, which is attached to three phosphate groups. 
So, the correct option is 'False'.

Which of the following cell organelles in concerned with photophosphorylation?

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

  1. Mitochondria

  2. Plastochondria

  3. Chloroplast

  4. More than one option is concerned

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Correct Option: C
Explanation:

The synthesis of ATP is called phosphorylation. If it occurs in the presence of light, it is called photophosphorylation, that occurs during photosynthesis in the chloroplast. Mitochondria perform oxidative and substrate level phosphorylation.

Hence, the correct answer is 'Chloroplast'

Which option is not correct for chemiosmotic theory?

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

  1. ATP synthesis is linked with proton gradient

  2. Break down of proton gradient releases energy

  3. ATPase enzyme act as pump to break proton gradient

  4. It is applicable for photo phosphorylation and oxidative phosphorylation

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Correct Option: C
Explanation:

  • There is a proton gradient created across the thylakoid membrane. The breakdown of this gradient is important because it leads to the release of energy. The gradient is broken down due to the movement of protons across the membrane to the stroma through the transmembrane channel ADP ATP of the F0 of the ATPase. 
  • The ATPase enzyme consists of two parts: F0 and F1. This breakdown provides enough energy to cause a conformational change in the F1 particle of the ATPase, which makes the enzyme synthesize ATP.

So, the correct option is 'ATPase enzyme act as a pump to break proton gradient'.

How many ATP - synthesised during complete oxidation of 3 molecule acetyl co A :

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

  1. 12 ATP

  2. 24 ATP

  3. 36 ATP

  4. 6 ATP

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Correct Option: A

The total number of ATP produced when one molecule of glucose is partially oxidised into lactic acid is: 

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

  1. 2

  2. 10

  3. 8

  4. 36

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Correct Option: A

Read the following statements : 
a) $F _0$ part of ATPase is associated with breakdown of proton gradient.
b) A H - carrier contributes in creation of proton gradient.
c) Movement of electrons in ETS is coupled to pumping of protons into the lumen.
d) Formation of $NADPH + H^+$ is related with the creation of proton gradient.
How many of the above statements are correct ?

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

  1. Two

  2. One

  3. Four

  4. Three

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Correct Option: A

Centrioles, cilia, flagella, and basal bodies have remarkably similar structural elements and arrangements. This leads us to which of the following as a probable hypothesis ?

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

  1. Disruption of one of these types of structure should necessarily disrupt each of the others as well.

  2. Loss of basal bodies should lead to loss of all cilia, flagella and centrioles

  3. Motor proteins such as dynein must have evolved before any of these four kinds of structure.

  4. Natural selection for motility must select for microtubular arrays in circular patterns.

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Correct Option: A,D

Which of the following is not required for chemiosmotic process?

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

  1. Proton gradient

  2. Spliting of water

  3. ATP synthase enzyme

  4. Closed membrane system

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Correct Option: D
Explanation:
A. Proton gradient is required because the breakdown of this gradient leads to release of energy.
B. Splitting of water is required which takes place on the inner side of the membrane and the protons that are produced, they accumulate within the lumen of the thyllakoids.
C. ATP synthase enzyme is required that allows diffusion of protons back across the membrane, this releases energy to activate ATPase enzyme which catalyses the formation of ATP.
D. Closed membrane system is not required. Only a membrane is required for the development of a proton gradient across the membrane of the thyllakoid and the proton accumulation is towards the inside of the membrane.
So, the correct answer is 'Closed membrane system'.

How many ATP molecule could maximally be generated from one molecule of glucose, if the complete oxidation of one mole of glucose to $CO _{2}$ and $H _{2}O$ yields $686$ kcal and useful chemical energy available in the high energy phosphate bond of one mole of ATP is $12\ kcal$.

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

  1. Fifty-seven

  2. One

  3. Two

  4. Thirty

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Correct Option: A

Chemiosmosis hypothesis given by Peter Mitchell proposes the mechanism of

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

  1. Synthesis of NADH.

  2. Synthesis of ATP.

  3. Synthesis of FADH$ _2$.

  4. Synthesis of NADPH.

Show answer
Correct Option: B
Explanation:
Chemiosmosis or chemiosmotic theory is given by Peter Mitchell explains the synthesis of ATP in the chloroplast. During the process of photosynthesis, the synthesis of ATP causes proton gradient to develop due to the accumulation of protons in thylakoid lumen that are formed by splitting of water. As the electron moves through the photosystem, protons are transported across the membrane. Now NADP reductase (enzyme) in stroma along with the electron acceptor removes protons along with the reduction of NADPH + H+. This causes proton gradient across the thylakoid membrane. The ATPase enzyme has a channel which allows the flow of proton through it and during this process the ATP is synthesised. Thus the correct answer is option B.