Tag: atp

Questions Related to atp

................ is the change in the value of a quantity with change in another variable.

bio-chemistry plant physiology active transport and passive transport types of plant transport atp

  1. Variant

  2. Valency

  3. Gradient

  4. Density

Show answer
Correct Option: C
Explanation:

Gradient is the change in the value of a quantity with change in another variable. Example time, solute concentration, pressure potential, solute potential, etc.

Density is the degree of compactness of a substance.
Valency is the number of electrons an atom can donate, share or accept to achieve a stable octet.
Variant is a quantity that changes its value.
So the correct answer is 'Gradient'.

Which of the following prevents an ion to cross the plasma membrane via simple diffusion?

bio-chemistry plant physiology active transport and passive transport types of plant transport atp

  1. Ions are too large.

  2. Ions carry a charge.

  3. Ions are hydrophobic.

  4. Ions do not produce a concentration difference.

  5. Ions cannot interact with membrane-bound proteins.

Show answer
Correct Option: B
Explanation:

Ions are small atoms or molecules carrying an electric charge. The core of plasma membrane is composed of nonpolar hydrophobic lipid tails and prevent simple diffusion of these charged particles. Thus, the correct answer is B. 

If the amount of an ion absorbed by a root hair cell at $0^{0}C$ is 5 gm and at $20^{0}C$ is 20 gm. The amount of this ion absorbed actively should be

bio-chemistry plant physiology active transport and passive transport types of plant transport atp

  1. 25 gm

  2. 20 gm

  3. 15 gm

  4. 5 gm

Show answer
Correct Option: C
Explanation:

At 0 degree Celsius the respiration rate will be zero. At 20 degree Celsius only the respiration process will take place. Hence, the 5 gm initially absorbed is due to physical diffusion of mineral ions from a region of high to low concentration. Later on, respiration occurs, then extra 15 grams are actively absorbed.

Which of these is/are not a property of facilitated transport?
(a) Requires special membrane proteins
(b) Highly selective
(c) Uphill transport
(d) Requires ATP energy

bio-chemistry plant physiology active transport and passive transport types of plant transport atp

  1. a and b only

  2. c and d only

  3. a and c only

  4. b and c only

  5. b and d only

Show answer
Correct Option: B
Explanation:
  • Facilitated transport or diffusion or passive-mediated transport can be defined as the process of spontaneous passive transport of molecules or ions across a cell membrane through the specific transmembrane integral proteins.
  • It does not require the ATP molecules and is the diffusion is downhill.
  • So, the correct answer is 'c and d only'.

Which does not pertain to facilitated transport?

bio-chemistry plant physiology active transport and passive transport types of plant transport atp

  1. Uphill transport

  2. High selectively

  3. Transport saturation

  4. Requirement of special membrane proteins

Show answer
Correct Option: A
Explanation:

Facilitated transport is the movement of molecules across a membrane through special transport proteins.

The movement is in accordance with the concentration gradient and hence a downhill transport.
Transport proteins provide high selectivity and transport only certain molecules.
Example: Ion channels, aquaporins, etc.
So the correct answer is 'Uphill transport'.

Choose the correct statement regarding facilitated diffusion:

bio-chemistry plant physiology active transport and passive transport types of plant transport atp

  1. It is fast process

  2. Expenditure of ATP occurs

  3. Break down the concentration gradients

  4. Does not requires special membrane proteins

Show answer
Correct Option: A

Which of the following is not true of the carrier molecules involved in facilitated diffusion?

bio-chemistry plant physiology active transport and passive transport types of plant transport atp

  1. They increase the speed of transport across a membrane

  2. They concentrate solute molecules on one side of the membrane

  3. They have specific binding sites for molecules they transport

  4. Transport protein may undergo conformational change upon binding of solutes

Show answer
Correct Option: A

Which of the following have no effect at rate of facilitated diffusion?

bio-chemistry plant physiology active transport and passive transport types of plant transport atp

  1. Transport saturation

  2. Presence and absence of membrane protein

  3. Low ATP concentration

  4. Concentration gradient difference

Show answer
Correct Option: A
Explanation:

Facilitated diffusion is the movement of water and other substances against the concentration gradient. The movement is through ions channels or membrane proteins which are present on the surface of the membrane. It requires the energy for the movement of substances. The movement is dependent upon the concentration gradient.

So, the correct option is 'Transport saturation'.

Facilitated diffusion

bio-chemistry plant physiology active transport and passive transport types of plant transport atp

  1. Needs a carrier protein

  2. Is an active process

  3. Occurs against the concentration gradient

  4. Needs ATP

Show answer
Correct Option: A
Explanation:

Substances having a hydrophilic moiety find it difficult to pass through the membrane. Their movement has to be facilitated. So, facilitated diffusion needs a 'carrier protein'. 

Thus, the correct answer is 'Needs a carrier protein.'

Select the incorrect statement regarding facilitated diffusion.

bio-chemistry plant physiology active transport and passive transport types of plant transport atp

  1. It is a very specific process

  2. It is a passive process

  3. It helps the hydrophilic substances to be transported across the membrane

  4. It is faster than active process

Show answer
Correct Option: D