Tag: carbohydrate metabolism

Questions Related to carbohydrate metabolism

Total number of ATP molecules produced per glucose molecule in eukaryotic cell is

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

  1. 38

  2. 36

  3. 24

  4. 12

Show answer
Correct Option: B
Explanation:

In eukaryotic cells, Complete breakdown of one glucose molecule in to carbon dixoide and water using oxygen produces 36 ATP molecules.

So the correct option is '36'.

One $NADH _2 / NADPH _2$ yields

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

  1. 2 ATP

  2. 3 ATP

  3. 12 ATP

  4. 6 ATP

Show answer
Correct Option: B
Explanation:

One NADH$ _2$/NADPH$ _2$ yields 3 ATP during electron transport chain process.

So the correct option is '3 ATP.'

Metabolism of one palmitic acid yields 

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

  1. 36 ATP

  2. 56 ATP

  3. 129 ATP

  4. 48 ATP

Show answer
Correct Option: C
Explanation:

Oxidation of palmitic acid yields 7 NADH + 7 FADH2 + 8 acetyl-CoA in 7 cycles of mitochondrial beta-oxidation. Every acetyl-CoA yields 3 NADH + 1 FADH2 + 1 GTP (=ATP) during Krebs cycle. An average production of 3 ATP/NADH and 2 ATP/FADH2 using the respiratory chain, We get  131 ATP molecules. However, you have to use 2 ATP molecules for the initial activation of every fatty acid that is going to be oxidized in the mitochondria.

So the correct option is '129 ATP'.

Direct ATP yield during Krebs cycle per glucose molecule is

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

  1. 2

  2. 8

  3. 30

  4. 38

Show answer
Correct Option: A
Explanation:

During the Krebs cycle, the net yield obtained was 6 molecules of NADH + H+, 2 molecules of FADH2, 4 carbon dioxide molecules, and two molecules of ATP. 

So the correct option is '2.' 

How many ATP molecules are released when one molecule of glucose is oxidised in our liver cells?

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

  1. 36

  2. 38

  3. 2

  4. 8

Show answer
Correct Option: B
Explanation:

38 ATP molecules are produced for the oxidation of one molecule of glucose. 2 from glycolysis, 2 from the Citric acid cycle, and about 34 from the electron transport system.

So the correct option is '38.'

How many ATPs are formed per glucose molecule in Krebs cycle?

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

  1. 2

  2. 24

  3. 6

  4. 28

Show answer
Correct Option: D
Explanation:

During the process of Krebs cycle 2 molecules of ATP, 8 molecules of NADH and 2 molecules of FADH2 were produced per molecule of glucose. A total of 28 ATPs are produced during Krebs cycle per a glucose molecule.

So the correct option is '28.'

From the oxidation of one molecule of palmitic acid (fatty acid), the number of ATP molecules gained as net are

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

  1. $131$

  2. $129$

  3. $38$

  4. $142$

Show answer
Correct Option: B
Explanation:

The oxidation of fatty acid occurs in the following step in mitochondria:

1. activation of fatty acid
2. beta-oxidation
3. Kreb's cycle
Palmitic acid is made up of 16 carbons, so going by the formula C$ _{2n}$, then 2n=16 for palmitic acid, hence, n=8. So, 8 acetyl Co-A are produced. Now, n-1 will be the number of NADH and FADH$ _{2}$ produced, so, n-1=7 for palmitic acid. Hence, there will be 7 FADH$ _{2}$ and 7 NADH.
Now, 1 NADH gives 3 ATP, so 7 NADH will give 21 ATP
          1 FADH$ _{2}$ gives 2 ATP, so 7  FADH$ _{2}$ will give 14 ATP
          1 Acetyl Co-A through Kreb's cycle gives 12 ATP, so 8 Acetyl Co-A will give 96 ATP.
Hence, a total of 131 ATP will be formed. But 2 ATPs have been used in the activation of the fatty acid in the first step so, 131-2=129 ATPs as net will be formed. 
Hence, the correct answer is '129'

In aerobic respiration,if 38 molecules of ATP are produced,then the number of ATP produced in glycolysis (X), pyruvate to acetyl- CoA (Y) and Krebs cycle (Z) will be

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

  1. X- 2,Y-6,Z-30

  2. X-8,Y-6,Z-24

  3. X-8,Y-10,Z-24

  4. X-2,Y-12,Z-24

Show answer
Correct Option: A
Explanation:
  •  Glycolysis: (2 ATP)
ATP formation by substrate phosphorylation = 4 ATP
ATP consumed in Glycolysis = 2 ATP 
  •  Pyruvate to Acetyl CoA: (2 NADH$ _{2}$ = 6 ATP) 
  • Kreb's Cycle: (30 ATP)
ATP formation by substrate phosphorylation = 2 ATP
ATP formation by oxidative phosphorylation = 28 ATP
So, the correct option is 'A) X- 2, Y - 6 ,Z-30'.