Tag: transport of molecules

Questions Related to transport of molecules

Movement of ions r molecules against electrochemical gradient is called ______________.

biology movement in and out of the cell transport of molecules osmosis and plasmolysis plant water relation

  1. Pinocytosis

  2. Diffusion

  3. Active transport

  4. Brownian movement

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Correct Option: C

Active absorption is affected by:

biology movement in and out of the cell transport of molecules osmosis and plasmolysis plant water relation

  1. Osmotic concentration

  2. Associate tissue structures

  3. Transpiration

  4. Sucking capacity of root hair

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Correct Option: A
Explanation:

Active absorption refers to absorption against the concentration gradient. Absorption of a solute from a region of low concentration to a region of higher concentration by the help of energy, is called active absorption. Hence, active absorption depends on osmotic concentration.

Active transport involves the transport of molecules across a cell membrane.
In order to establish and maintain a concentration gradient, which of the following condition is suitable?

biology movement in and out of the cell transport of molecules osmosis and plasmolysis plant water relation

  1. Free energy is used to drive molecules back-and-forth across the transmembrane protein.

  2. Free energy is used to drive molecules and across a transmembrane protein against the concentration gradient.

  3. No free energy is required.

  4. There must be an equal quantity of molecules on both sides of the membrane.

Show answer
Correct Option: B
Explanation:

Free energy obtained from hydrolysis of ATP is used for the movement of solutes against their concentration gradient across the plasma membrane using a transport transmembrane protein also called pump

So, the correct answer is 'Free energy is used to drive molecules and across a transmembrane protein against the concentration gradient'

In the light of carrier concept, the transport of ion across the membrane against concentration gradient is

biology movement in and out of the cell transport of molecules osmosis and plasmolysis plant water relation

  1. Passive process

  2. Non-osmotic process

  3. Osmotic process

  4. Active process

Show answer
Correct Option: D
Explanation:

According to carrier concept for transport of ion in plants, transport is mediated by specific carriers. When the ion is transported against the concentration gradient, the ion carrier is activated in presence of ATP and a kinase enzyme. The activated carrier forms a complex with an ion at the outer surface and transported in. Because this process involves ATP, hence, it is called active process.

Carrier proteins are involved in the

biology movement in and out of the cell transport of molecules osmosis and plasmolysis plant water relation

  1. Active transport of ions

  2. Passive transport of ions

  3. Water transport

  4. Both A and B

Show answer
Correct Option: D
Explanation:

Active transport is the movement of a substance across a membrane against its concentration gradient. Unlike channel proteins which only transport substances through membranes passively, carrier proteins can transport ions and molecules either passively through facilitated diffusion, or via secondary active transport.

Therefore D is the correct option. 

Active transport across biomembrane involves

biology movement in and out of the cell transport of molecules osmosis and plasmolysis plant water relation

  1. Production of ATP

  2. Requirement of energy

  3. Production of toxin

  4. Release of energy

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Correct Option: B
Explanation:
  • Active transport is a process by which molecules move across the cell membrane from a region of low concentration to a region of high concentration against the concentration gradient using energy.
  • This energy requirement is fulfilled by the ATP molecules (metabolic energy).
  • The substances which are transported across the cell membrane by active transport are- Na+, K+, Mg2+, and Ca2+.
  • So, the correct answer is 'Requirement of energy'.

Minerals are absorbed by the plants, through

biology movement in and out of the cell transport of molecules osmosis and plasmolysis plant water relation

  1. Pressure flow

  2. Diffusion

  3. Active transport

  4. Osmosis

Show answer
Correct Option: C
Explanation:

Minerals are absorbed by plants through active transport as minerals are present in the soil mostly in the form of charged particles which fail to move across cell membrane and concentration of minerals in the cell is usually greater than that present in the soil solution. Therefore, most of the minerals are absorbed by active mechanism involving expenditure of energy in the form of ATP.

Hence, C is the correct answer.

$Na^+ / K^+$ pump in a cell is an example of

biology movement in and out of the cell transport of molecules osmosis and plasmolysis plant water relation

  1. Osmosis

  2. Diffusion

  3. Passive transport

  4. Active transport.

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Correct Option: D

Active transport of ions by a cell requires

biology movement in and out of the cell transport of molecules osmosis and plasmolysis plant water relation

  1. High temperature

  2. Low temperature

  3. Alkaline pH

  4. ATP

Show answer
Correct Option: D
Explanation:
  • Active transport can be defined as the movement of molecules and ions across a cell membrane from a region of lower concentration (of the molecules) to the region of higher concentration i.e, movement of molecules occurs against the concentration gradient. 
  • This transport requires cellular or metabolic energy which is available in the form of ATP molecules produced within the cell.
  • So, the correct answer is 'ATP'.

Which is not true of active transport

biology movement in and out of the cell transport of molecules osmosis and plasmolysis plant water relation

  1. It is chemical process

  2. Energy is obtained from ATP

  3. Occurs through carrier molecules

  4. Not modified by enzymes.

Show answer
Correct Option: A