Tag: bio-chemistry

Questions Related to bio-chemistry

A cell with DPD = 5 is surrounded by A, B, C and D cells having O.P. and T.P. 5 and 4, 7 and 5, 3 and 2, zero and zero respectively. From which cell will the water withdraw faster?

bio-chemistry absorption by roots - the processes involved osmotic relations of plant cells transport across membrane imbibition and its importance

  1. D

  2. C

  3. B

  4. A

Show answer
Correct Option: A
Explanation:

DPD is the difference between Osmotic pressure and Turgor pressure. 

For cell A the DPD is 1.
For cell B the DPD is 2.
For cell C the DPD is 1
For cell D the DPD is 0.
So, the correct answer is 'D'.

Colligative property is :
1. Osmotic pressure
2. Vapour pressure
3. Cohesive force
4. Surface tension

bio-chemistry absorption by roots - the processes involved osmotic relations of plant cells transport across membrane imbibition and its importance

  1. 1, 2, 3

  2. 1, 2

  3. 2, 4

  4. 1, 3

Show answer
Correct Option: B
Explanation:

Colligative properties are the characteristics of solutions which depend on the ratio of the number of solute particles to the number of solvent molecules in a solution. It does not depend on the quality of the chemical species present.

Colligative properties include vapor pressure, elevation of boiling point, depression of freezing point and osmotic pressure because, over here all depends only on the number of dissolved particles.
So, the correct answer is option B.

A RBC and a plant cell having same O.P. are placed in distilled water, then 

bio-chemistry absorption by roots - the processes involved osmotic relations of plant cells transport across membrane imbibition and its importance

  1. None undergoes any change.

  2. Plant cell swells up and bursts but plant cell remains about the same size.

  3. RBC swells up and bursts but there is no change in plant cell.

  4. Both decrease in size and collapse.

Show answer
Correct Option: C
Explanation:

Distilled water is a hypotonic solution contained within the red blood cell membranes that is why distilled water will diffuse into the red blood cells and cause them to burst.

So, the correct answer is 'RBC swells up and burst but there is no change in the plant cell'.

If cells of onion peel and RBC are separately kept in hypotonic solution, what among the following will take place?

bio-chemistry absorption by roots - the processes involved osmotic relations of plant cells transport across membrane imbibition and its importance

  1. Both the cells will swell

  2. RBC will burst easily while cells of onion peel will resist the bursting to some extent

  3. A and B both are correct

  4. RBC and onion peel cells will behave similarly

Show answer
Correct Option: C
Explanation:

Hypotonic solution is a solution which contains lesser solute concentration. If RBC is kept in hypotonic solution then the water molecules will move from hypotonic solution to RBC. This process is called as osmosis in which the water molecules move from lower solute concentration to higher solute concentration through cell membrane RBC. Due to this, the cell membrane of RBC will not be able to tolerate the pressure and it will burst eventually. 
If onion peel is kept in hypotonic solution then the water molecules will move from hypotonic solution to onion cells. This process is called as osmosis in which the water molecules move from lower solute concentration to higher solute concentration through the cell wall of onion. As onion cell possess cell wall along with the cell membrane the onion cell will take a longer time to burst than RBC but it will burst eventually. 
So, the correct answer is option B.

Cells of onion peel and RBC are separately kept in hypotonic solution, what among the following will take place?

bio-chemistry absorption by roots - the processes involved osmotic relations of plant cells transport across membrane imbibition and its importance

  1. Both the cells will swell

  2. RBC will burst easily while cells of onion peel will resist the bursting to some extent

  3.  RBC and onion peel cells will behave similarly

  4. Both A and B

Show answer
Correct Option: D
Explanation:

When the cells are kept in a hypotonic solution, endosmosis occur, i.e., inward movement of water. This results in the swelling up of the cells. The RBCs burst easily because they are animal cells and do not have cell wall. The onion peel possess cell wall which makes it resistant to bursting due to swelling caused by endosmosis. Therefore, option D is correct.

What will happen when a Red Blood Cell (RBC) is kept in concentrated saline solution?

bio-chemistry absorption by roots - the processes involved osmotic relations of plant cells transport across membrane imbibition and its importance

  1. It will lose water and shrink

  2. It will absorb water and swell

  3. It will be remain unaffected

  4. None of the above

Show answer
Correct Option: A
Explanation:

When RBCs are kept in concentrated saline solution then such solution is said to be hypertonic. Hence, exosmosis i.e., water will move from inside to outside of RBC through its cell membrane due to this, RBCs will shrink.

So, the correct answer is option A.

Choose the correct answers from the alternatives given :
The relationship between osmotic pressure, turgor pressure and wall pressure is represented by

bio-chemistry absorption by roots - the processes involved osmotic relations of plant cells transport across membrane imbibition and its importance

  1. TP=OP+WP

  2. OP=TPWP

  3. WP = TP OP

  4. OP = TP + WP

Show answer
Correct Option: B
Explanation:

Wall pressure is equal and opposite to the turgor pressure.

TP =  WP 
Also, DPD/SP = OP- WP 
           WP = TP 
        DPD = OP - TP 
In fully turgid cells, turbo pressure is equal to osmotic pressure. Hence, division pressure deficit is zero in such case 
           OP = TP (in turgid cell) 
           DPD = 0 (zero) 
In fully plasmyzed cells, the value of turgor pressure becomes zero due to decrease in TP and increase of OP.
       TP = 0 
      SP/DPD = OP (in plasmolyzed cells) 
Now a days water potential is used which is equal to DPD.
    WP = DPD 
So, the correct option is 'Op= TP WP'.

Chemiosmosis hypothesis given by Peter Mitchell proposes the mechanism of

bio-chemistry biological oxidation oxidative phosphorylation living organisms and energy production glycolysis

  1. Synthesis of NADH.

  2. Synthesis of ATP.

  3. Synthesis of FADH$ _2$.

  4. Synthesis of NADPH.

Show answer
Correct Option: B
Explanation:
Chemiosmosis or chemiosmotic theory is given by Peter Mitchell explains the synthesis of ATP in the chloroplast. During the process of photosynthesis, the synthesis of ATP causes proton gradient to develop due to the accumulation of protons in thylakoid lumen that are formed by splitting of water. As the electron moves through the photosystem, protons are transported across the membrane. Now NADP reductase (enzyme) in stroma along with the electron acceptor removes protons along with the reduction of NADPH + H+. This causes proton gradient across the thylakoid membrane. The ATPase enzyme has a channel which allows the flow of proton through it and during this process the ATP is synthesised. Thus the correct answer is option B.

Riboflavin is essential in our diet, as it is required for the synthesis of

bio-chemistry biological oxidation oxidative phosphorylation living organisms and energy production glycolysis

  1. TPP

  2. COASH

  3. NAD

  4. FAD

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Correct Option: D

Major function of respiration is to produce

bio-chemistry biological oxidation oxidative phosphorylation living organisms and energy production glycolysis

  1. NADH $(H^+)$

  2. ATP

  3. Pyruvate

  4. $C _2H _5OH$

Show answer
Correct Option: B
Explanation:

Respiration is a process in which respiratory substrates are broken down through oxidation accompanying with the release of energy and its storage or conservation in the form of ATP with the release of carbon dioxide as a consequence. The actual mechanism of respiration is a stepwise process in which each step is catalyzed by a specific enzyme and the energy stored in the substrate is released in a stepwise series of reactions. The energy released in the process is used up in various energy-requiring processes of organisms. 

Thus, the correct answer is option B.