Tag: carbohydrate metabolism

Questions Related to carbohydrate metabolism

The net gain of ATP from one molecule of glucose in aerobic respiration is

bio-chemistry carbohydrate metabolism energy output living organisms and energy production respiration in cell

  1. 18 ATP

  2. 38 ATP

  3. 60 ATP

  4. 80 ATP

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Correct Option: B
Explanation:

If the food substances in living cells are oxidized in presence of oxygen, it is called aerobic respiration. It is the step-wise complete breakdown of the respiratory substrates like glucose into simpler molecules like $CO _2$ and water with the release of ATP. It is mostly seen in eukaryotic type of organisms. Each glucose molecule on complete oxidation gives 38 ATP molecules. 

How many PGAL are produced by glycolysis of 3 molecules of glucose? How many ATP are released by respiration of these PGAL till formation of $O _2$ and $H _2O$?

bio-chemistry carbohydrate metabolism energy output living organisms and energy production respiration in cell

  1. 4 PGAL-80 ATP

  2. 6 PGAL-160 ATP

  3. 4 PGAL40 ATP

  4. 6 PGAL-120 ATP

Show answer
Correct Option: D
Explanation:

Glycolysis of one molecule of glucose produces 2 PGAL, thus of three molecules will produce 6 PGAL.
Respiration of one molecule of glucose or 2 PGAL produces 38 ATP molecules, thus, of 6 PGAL will produce 114 ATP molecules. Out of the given options 120 ATP is the nearest correct answer. Thus the correct answer is option D.

Which of the following is not an electron transferring molecule?

bio-chemistry carbohydrate metabolism energy output living organisms and energy production respiration in cell

  1. ATP

  2. NAD$^{+}$

  3. Fe-S protein

  4. Co-enzyme Q

Show answer
Correct Option: A
Explanation:

Adenosine triphosphate is a nucleoside triphosphate used in cells as a coenzyme. It is often called the molecular unit of currency of intracellular energy transfer. ATP transports chemical energy within cells for metabolism. It is one of the end products of photophosphorylation, cellular respiration and fermentation and used by enzymes and structural proteins in many cellular processes, including biosynthetic reactions, motility and cell division. One molecule of ATP contains three phosphate groups.

Complete oxidation of 1 gm mole of glucose yields

bio-chemistry carbohydrate metabolism energy output living organisms and energy production respiration in cell

  1. 686 cal

  2. 6860 cal

  3. 68600 cal

  4. 686000 cal

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Correct Option: D
Explanation:

Complete oxidation of 1 gm mole (180 g) of glucose yields 686 Kcal, that is 686000 cal of energy. It means, 1 g of glucose oxidizes to produce 3.8 Kcal.

Thus, the correct answer is option D.

During which stage in the complete oxidation of glucose are the greatest number of ATP molecules formed from ADP -

bio-chemistry carbohydrate metabolism energy output living organisms and energy production respiration in cell

  1. Glycolysis

  2. Krebs cycle

  3. Electron transport chain

  4. Conversion of pyruvic acid to acetyl CoA

Show answer
Correct Option: C
Explanation:

In glycolysis 4 ATP and 2NADH2 molecules are formed. These 2NADH2  molecules go to electron transport chain. In oxidative decarboxylation no ATP molecule is formed but two molecules of 2NADH2  are formed from two molecules of pyruvate. These two NADH2 go to electron transport chain. In Kreb's cycle 2 ATP, 6NADH2 and 2FADH2 molecules are formed from two molecule of acetyl Co-A. These NADH2 and 2FADH2  go to electron transport chain. In electron transport chain all 2NADH2   and 2FADH2  pass to electron carriers and yield 3 ATP and 2 ATP molecules per 2NADH2   and 2FADH2  respectively. Thus,  4 ATP are formed in glycolysis, 2 ATP in Krebs cycle and 34 ATP from electron transport chain. 40 ATP and 2 ATP molecules are used during glycolysis. So, net gain of ATP molecules during one complete oxidation of a glucose molecule is 38 ATP.


So, the correct answer is 'Electron transport chain'.

The rate of respiration undergoes a sharp rise followed by a when certain fruits ripen. This phenomenon is known as ____________.

bio-chemistry carbohydrate metabolism energy output living organisms and energy production respiration in cell

  1. Climatic rise

  2. Climatic fall

  3. Climacteric rise

  4. Anaerobiosis

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Correct Option: A

Out of $38$ ATP molecule how many ATP are formed by substrate level phosphorylation by aerobic respiration of $1$ glucose?

bio-chemistry carbohydrate metabolism energy output living organisms and energy production respiration in cell

  1. $2$

  2. $3$

  3. $4$

  4. Zero

Show answer
Correct Option: A
Explanation:

Substrate level phosphorylation involves the conversion of 1,3 bisphosphoglycerate to 3 phosphoglycerate producing ATP.

For 1 molecule of glucose, 2 (1,3 bisphosphoglycerate) are formed, hence 2 ATP are formed.  

Number of ATP molecules formed during aerobic respiration in break down of one glucose molecule via malate aspartate shuttle is 

bio-chemistry carbohydrate metabolism energy output living organisms and energy production respiration in cell

  1. 38

  2. 18

  3. 28

  4. 4

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Correct Option: A

For the synthesis of 1 ATP in oxidative phosporylation how many ${H}^{+}$ required?

bio-chemistry carbohydrate metabolism energy output living organisms and energy production respiration in cell

  1. $3$

  2. $2$

  3. $4$

  4. $1$

Show answer
Correct Option: C
Explanation:

For synthesis of 1 ATP, 4 H+ are required. ATP synthase synthesizes 1 ATP for every 4 H+ that passes through it. 

During aerobic respiration, all the ATPs are synthesized as a result of _______________.

bio-chemistry carbohydrate metabolism energy output living organisms and energy production respiration in cell

  1. Oxidative phosphorylation

  2. Oxidative and substrate level phosphorylation

  3. Substrate level phosphorylation

  4. Oxidative and phosphorylation

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Correct Option: A