Tag: living organisms and energy production

Questions Related to living organisms and energy production

The organelle responsible for ATP formation is  

  1. Quantasome

  2. Thylakoid

  3. Chondriosome

  4. Mitochondria


Correct Option: C,D
Explanation:
 Name of the organelle  Function
 Quantasome  These are the particles found in the membrane of thylakoid and in which process of photosynthesis takes place.
 Thylakoid  Carry out the light reactions of photosynthesis
 Chondriosome Another name of a mitochondrion. Responsible for ATP formation
 MItochondria The two stages of respiration take place in the mitochondria. Krebs cycle occurs in the cristae of the mitochondria. Oxidative phosphorylation occurs on the membranes. The energy is released at the end of respiration in the form of ATP.

So, the correct answer is ' Mitochondria and Chondriosome '

In prokaryotic cells, the number of ATP generated form one glucose molecule is _______

  1. $36$

  2. $38$

  3. $34$

  4. $32$


Correct Option: B
Explanation:

In the eukaryotic ell, the aerobic respiration occurs in mitochondria as well as the cytoplasm. The Electron Transport Chain (ETC) that yields the maximum ATPs is located in the inner membrane of the mitochondria. So, the NADH made during the glycolysis in cytoplasm have to be transferred to the mitochondria using the shuttle system and for this, 2 ATPs are consumed. However, in the bacterial cell, since there is no mitochondria, the whole process of respiration occurs within the cytoplasm so no ATP is consumed in transporting across the organelle. Therefore, 38 ATPs are made form one glucose in bacteria while 36 are made in an eukaryotic cell.

Hence, the correct answer is '38'

Energy released by oxidation of one molecule of glucose is -

  1. 800 K.cal

  2. 695 K. cal

  3. 686 K.cal

  4. 700 K.cal


Correct Option: C
Explanation:

When 1 mol (180 g) of glucose reacts with oxygen under standard conditions, 686 kcal of energy is released. 36 ATP synthesised in aerobic respiration. Total free energy stored as high energy phosphate bonds in ATP is therefore 252kcal. The remaining energy is lost. So, the correct option is '686 K.cal'.


How many $NADH+ H^+$ molecules are released from a single Krebs' cycle?

  1. $3$

  2. $6$

  3. $12$

  4. $8$


Correct Option: B

The energy stored in one molecule of NADPH and one molecule of ATP are ....... and ...... respectively.

  1. 52 kcal, 7 kcal

  2. 520 kcal, 70 kcal

  3. 150 kcal, 22 kcal

  4. 650 kcal, 90 kcal


Correct Option: A
Explanation:

Nicotinamide adenine dinucleotide phosphate is abbreviated as NADP, is a cofactor used in anabolic reactions, such as lipid and nucleic acid synthesis, which require NADPH as a reducing agent. It produces 52 kCal of energy from one molecule. Adenosine triphosphate used in cells as a energy currency, often called the molecular unit of currency of intracellular energy transfer. ATP is therefore continuously recycled in organisms: the human body, which on average contains only 250 grams of ATP.  One molecule of ATP produces 7kCal of energy.

How many ATP are synthesized per sucrose molecule(gross synthesis) in aerobic respiration through substrate level phosphorylation?

  1. $10$

  2. $12$

  3. $30$

  4. $76$


Correct Option: C
Explanation:

C- In substrate-level phosphorylation, 2 ATP are synthesized from glycolysis and 2 ATP from Krebs cycle Oxidative phosphorylation that is, 2 × 1.5 ATP or 2 × 2.5 ATP (in malate-aspartate shuttle). Thereby, from the oxidative decarboxylation of pyruvate there shall be 2 NADH+H+ and 6 from Krebs cycle making it – (a) 8 × 2.5 ATP & 2 FADH2 from the Krebs cycle, (b) 2 × 1.5 ATP; thus summing it up to 4 + 3 (or 5) + 20 + 3 = 30 (or 32) ATP per molecule of glucose.

The radiant energy is stored in the form of chemical energy in

  1. NADP

  2. Stored food

  3. RNA

  4. DNA


Correct Option: B
Explanation:

Photosynthesis is an energy conversion process. During photosynthesis green plants trap solar energy and synthesize sugars. Thus light energy present in photons is converted to chemical energy, which is trapped in the bonds of sugar molecules.

Complete oxidation of 1 gm mol of glucose gives rise to ................. calories.

  1. 6860000 

  2. 686000 

  3. 68600 

  4. 6860 


Correct Option: B
Explanation:

At pH 7.0 and temperature 298 K, the standard free energy change of oxidation of glucose is -686 Kilocalories per mole or -2840 Kilojoules per mole. The negative values indicate that oxidation of glucose is an exergonic or energy releasing process.

Common immediate source of energy for cellular activity is

  1. Glucose.

  2. Aldohexose.

  3. ATP.

  4. NAD.


Correct Option: C
Explanation:

Adenosine triphosphate (ATP) is a nucleotide with three phosphates. It is the universal energy currency for all cellular metabolic processes. Endergonic processes are driven by energy input using hydrolysis of ATP. Exergonic processes are coupled to ATP synthesis. 

How many ATP forms in aerobic respiration of eukaryotic cell?

  1. 28 ATP

  2. 36 ATP

  3. 20 ATP

  4. 40 ATP


Correct Option: B
Explanation:

Overall production of aerobic reaction is 24 (Krebs cycle) + 6 (oxidative decarboxylation) + 6 (glycolysis), i.e., 36 ATP molecules.