Tag: bio-chemistry

Questions Related to bio-chemistry

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

  1. 36

  2. 38

  3. 2

  4. 8


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?

  1. 2

  2. 24

  3. 6

  4. 28


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

  1. $131$

  2. $129$

  3. $38$

  4. $142$


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

  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


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'.

Which one is wrong combination?

  1. $N _2$-Amino acid

  2. Fe-cytochrome

  3. Na-Protein

  4. Mg-Chlorophyll

  5. P-DNA


Correct Option: C
Explanation:

Na- Protein is wrong combination as Nitrogen (N) is needed for the protein formation. Nitrogen is the main constituent of the amino acid that helps in the formation of protein

Thus, the correct answer is option C.

Which of the following element is not essential for plants?

  1. Iron

  2. Zinc

  3. Potassium

  4. Iodine


Correct Option: D
Explanation:

Plants may absorb a number of minerals that are not essential for their growth. Iodine is a non essential mineral element. Iron, zinc and potassium are essential mineral elements.

Nutrition involving engulfment` 'of the whole or part of a plant or an animal in solid or in liquid state is known

  1. Holozoic

  2. Saprozoic

  3. Parasitic

  4. Symbiotic


Correct Option: A

Which of the group of elements is not essential for a normal plant?

  1. K, Ca, Mg

  2. Fe, Zn, Mn, B

  3. Pb, I, Na

  4. Mg, Fe, Mo


Correct Option: C
Explanation:

The plant ash reveals the presence of 40 elements but all are not essential for plant nutrition, only a few are essential for growth and development of plants. These are called as the essential elements. The essential elements may be grouped as major elements or macronutrients and trace elements or micronutrients, based on their requirement by plants. 

Major elements or macronutrients are required in large amounts and form the plant constituents. These include carbon, hydrogen, oxygen, nitrogen, phosphorus, potassium, calcium, magnesium and sulphur. These elements form an integral part of complex organic molecules. Some of these elements help in the functioning of enzyme systems. The sources of macronutrients are generally the soil or the atmosphere. 
Trace elements or micronutrients are elements, like iron, boron, manganese, copper, zinc and molybdenum. They are required for plants only in very small amounts but these are indispensable for the normal growth and development of plants. 
Lead, Iodine and sodium are generally not required by plants and are non essential elements for plant mineral nutrition.

Engulfing of food in solid or fluid state is

  1. Saprozoic nutrition

  2. Parasitic nutrition

  3. Saprophytic nutrition

  4. Holozoic nutrition


Correct Option: D
Explanation:
Holozoic nutrition is a type of heterotrophic nutrition that is characterized by the ingestion and internal processing of gaseous, liquid or solid food particles Protozoa, such as amoebas, and most of the animals, exhibit this type of nutrition. There are several stages of holozoic nutrition, which often occur in separate compartments within an organism :
  • Ingestion 
  • Digestion
  • Absorption
  • Assimilation and
  • Egestion.
Hence, the engulfing of food in a solid or liquid state is holozoic nutrition.
So, the correct answer is 'holozoic nutrition'.

Which of the following occurs in maximum concentration in blood plasma (extracellular fluid)?

  1. K$^+$

  2. Mg$^{+2}$

  3. Ca$^{+2}$

  4. Na$^+$


Correct Option: D
Explanation:

Term ECF is used for "Extra Cellular Fluid". The outside environment of a living cell is rich in sodium where as interior of a living cell is always rich in potassium ions. This differential concentration is maintained by sodium potassium pump operating in cell membrane of living cells.