Tag: bio-chemistry

Quizzes (82) Questions (1918)

Questions Related to bio-chemistry

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

The idea that pH gradients could provide energy for ATP formation in chloroplasts and mitochondria was first proposed by ____________.

  1. Bassham

  2. Hill

  3. Mitchell

  4. Thompson
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Peter Mitchell proposed the chemiosmotic hypothesis, which states that proton gradients across thylakoid and inner mitochondrial membranes provide the driving force for ATP synthesis.

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

Which of the following step of photosynthesis is not directey involve in ATP synthesis or consumption?

  1. Corboxylation of dark Rection

  2. Reduction of dark reaction

  3. Cyclic photo phosphorylation of light reaction

  4. Regeneration of dark reaction
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Carboxylation of the dark reaction (Calvin cycle) does not directly involve ATP synthesis or consumption. The enzyme RuBisCO catalyzes CO2 fixation with RuBP without ATP. Both reduction and regeneration phases consume ATP, and cyclic photophosphorylation produces ATP.

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

Direct gain of ATP from one mole of glucose during glycolysis or EMP pathaway ____________.

  1. 2 ATP

  2. 6 ATP

  3. 36 ATP

  4. 38 ATP
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Glycolysis (EMP pathway) produces a net gain of 2 ATP molecules per glucose molecule through substrate-level phosphorylation. While 4 ATP are grossly produced, 2 ATP are consumed in the energy investment phase, resulting in a net yield of 2 ATP.

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

Photosynthetic oxygen producing cells differ from non-oxygen producing cells in that the former.

  1. Produce one ATP whereas the latter produce two
  2. Produce no NADPI-$1$ whereas the latter do

  3. Reduce ferredoxin whereas the latter do not

  4. Contain and use both photo systems I and II
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Oxygen-producing photosynthesis (oxygenic photosynthesis, found in cyanobacteria, algae, and plants) relies on a non-cyclic electron transport chain that requires both Photosystem I and Photosystem II working in series. Non-oxygen producing organisms (like some bacteria) typically use anoxygenic photosynthesis with only a single photosystem.

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

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

  1. $\displaystyle Two$
  2. $\displaystyle Thirty$
  3. $\displaystyle Fifty \ seven$
  4. $\displaystyle One$
Reveal answer Fill a bubble to check yourself
A Correct answer
Multiple choice bio-chemistry biological oxidation chemiosmotic hypothesis living organisms and energy production mechanism of photosynthesis

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 $H _{2}O$ yields $686\ kcal$ and the useful chemical energy available in the high energy phosphate bond of one mole of ATP is $12\ kcal$?

  1. Two

  2. Thirty

  3. Fifty seven

  4. One
Reveal answer Fill a bubble to check yourself
A Correct answer
Multiple choice bio-chemistry biological oxidation chemiosmotic hypothesis living organisms and energy production mechanism of photosynthesis

The primary reaction in photosynthesis is photochemical and takes place in the chloroplast. It is accomplished by a chain of electron carriers with phosphorylation of ADP to ATP. The actual site for this reaction is?

  1. Intrathylakoid space

  2. Thylakoid membrane

  3. Chloroplast envelope

  4. Stoma
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The light-dependent reactions of photosynthesis, involving electron transport chains and photophosphorylation, take place across the thylakoid membrane where photosystems and ATP synthase complexes are embedded.