Tag: bio-chemistry

Questions Related to bio-chemistry

The energy consumed during the conversion of ADP into ATP is 

  1. 73000 cal/mole

  2. 686000 cal/mole

  3. 8000 cal/mole

  4. 7300 cal/mole


Correct Option: D
Explanation:

Adenosine-5'-triphosphate (ATP) is comprised of an adenine ring, a ribose sugar, and three phosphate groups. ATP is often used for energy transfer in the cell. ATP synthase produces ATP from ADP or AMP + Pi. The energy consumed during the conversion of ADP into ATP is 7300 cal/mole.

Net gain of ATP in prokaryotes from a molecule of glucose when oxidized is

  1. 40

  2. 38

  3. 36

  4. 34


Correct Option: B
Explanation:

A total 38 ATP molecules (2 ATP molecules from glycolysis, 2 from Kreb's cycle and 34 from electron transport system) are produced per molecule of glucose oxidised in aerobic prokaryotes. Whereas, the net gain in most of the eukaryotes is 36 ATP molecules (as 2 ATP molecules are consumed intransporting $NADH _2$ into mitochondria). 

A single ATP produce 

  1. -7.3 kcal

  2. 10 kcal

  3. 12 kcal

  4. 100 kcal


Correct Option: A
Explanation:

ATP stands for adenosine triphosphate. It is complex molecule that contains the nucleoside adenosine and a tail consisting of three phosphates. It is the primary energy currency. A single ATP produce -7.3 kcal.

How many ATP are formed from NADPH$^{+}$ to NAD$^{+}$?

  1. 2 ATP

  2. 3 ATP

  3. 6 ATP

  4. 4 ATP


Correct Option: B
Explanation:

$NAD^+$ and $NADP^+$ are coenzymes, that function in oxidation-reduction reactions. 3 ATP are formed from the conversion of  $NADPH^+$ to $NAD^+$.

 Energy produced during aerobic respiration of glucose 

  1. 637 kcal

  2. 640 kcal

  3. 686 kcal

  4. 693 kcal


Correct Option: C
Explanation:

 Aerobic respiration takes place through a series of reactions such as Glycolysis, Oxidative decarboxylation of pyruvates, Citric acid cycle and Oxidative phosphorylation. Being efficient in extracting chemical energy, the total free energy produced during the process is 686 kcal. Thus, the correct answer is option C.

The net gain of energy from one molecule of glucose during aerobic respiration is 

  1. 2 ATP

  2. 36 ATP

  3. 38 ATP

  4. 15 ATP


Correct Option: C
Explanation:

38 molecules can be made per oxidised glucose molecule during cellular respiration. It is possible by the yield of ATP molecules from Krebs cycle, glycolysis and electron transport system. 

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

  1. 18 ATP

  2. 38 ATP

  3. 60 ATP

  4. 80 ATP


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 $H _2O$?

  1. 4 PGAL-80 ATP

  2. 6 PGAL-160 ATP

  3. 4 PGAL40 ATP

  4. 6 PGAL-120 ATP


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?

  1. ATP

  2. NAD$^{+}$

  3. Fe-S protein

  4. Co-enzyme Q


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

  1. 686 cal

  2. 6860 cal

  3. 68600 cal

  4. 686000 cal


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.