Tag: bio-chemistry

Questions Related to bio-chemistry

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

Show answer
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

ATP is known as energy currency of a cell. ATP is synthesized from ADP and Pi. The reaction is catalyzed by an enzyme called as ATP synthase. When the enzyme and substrate (ADP) are distant inside the cell, the reaction cannot take place spontaneously. Which of the following statements best explains the cause for the ATP synthase and ADP to interact?

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

  1. Electronegativity of ADP attracts ATP synthase

  2. ADP will be actively pumped to ATP synthase

  3. Random movements will bring ADP to ATP synthase

  4. ADP and ATP synthase always remain bound to oxysomes

Show answer
Correct Option: A

How many ATP molecules could maximally be generated from one molecule of glucose, if the complete oxidation of one mole of glucose to $CO _2$ and $H _2O$ yields $686$kcal and the 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. $1$

  2. $2$

  3. $30$

  4. $57.1$

Show answer
Correct Option: A

Calvin cycle has three stages.
$1$. Reduction during which carbohydrate is formed at the expense of photochemically made ATP and NaDPH.
$2$. Regeneration during which carbon dioxide acceptor $1, 5$-RuBP is formed.
$3$. Carboxylation during which $CO _2$ combines with $1, 5-$RuBP.
Identify the correct sequence.

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

  1. $3, 1, 2$

  2. $3, 2, 1$

  3. $1, 2, 3$

  4. $2, 1, 3$

Show answer
Correct Option: A