Tag: movement in and out of the cell

Questions Related to movement in and out of the cell

Choose the correct answer from the alternatives given.
Which is the best definition of active transport?

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

  1. Movement of molecules from an area of their higher concentration to an area of their lower concentration

  2. Movement of water across a semi-permeable membrane from an area of high water concentration to an area of lower water concentration

  3. Movement of molecules from an area of their lower concentration to an area of their higher concentration

  4. Movement of a substance against its concentration through the release of energy from ATP

Show answer
Correct Option: D
Explanation:
In one form of transport across the cell membrane, ATP is utilized. The utilization of an ATP molecule provides the cell with an energy boost which enables the transport of different molecules across the cell membrane against their concentration gradient. This is termed as active transport of molecules across the cell membrane.

So, the correct answer is 'Movement of a substance against its concentration through the release of energy from ATP'.
Which of the following is an energy-dependent process?
biology movement in and out of the cell transport of molecules osmosis and plasmolysis plant water relation

  1. Facilitated diffusion

  2. Active transport

  3. Endosmosis

  4. Exosmosis

Show answer
Correct Option: B
Explanation:

Active transport is an energy dependent process, in which ATP is utilised.

Which of the following is an energy dependent process?

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

  1. Facilitated diffusion

  2. Active transport

  3. Endosmosis

  4. Exosmosis

Show answer
Correct Option: B
Explanation:

Active transport (secretion) is an energy-dependent process that selectively moves a substance against its electrochemical gradient across a cell membrane. It is an energy dependent process, in which ATP is utilised.

Thus the correct option is B. 

Uphill transport i.e., movement of substances from their lower concentration to their higher concentration occurs in

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

  1. Simple diffusion

  2. Facilitated diffusion

  3. Active transport

  4. Both B and C

Show answer
Correct Option: C
Explanation:

In active transport, the movable carrier proteins are called pumps. They employ ATP energy for transport across the membrane. It is uphill transport, i.e., against concentration gradient and is faster than passive transport. The rate of active transport reaches the maximum when all the protein pumps are being used in transport(saturation effect). Carrier proteins are highly specific like enzymes. They are also sensitive to inhibitors that react with protein side chains. So, the correct answer is 'Active transport'.

Channel proteins allow ions that would not normally pass through the cell membrane to go through the channel. What properties of the proteins are responsible for this? 

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

  1. The channels are often composed of charged or polar $R$ groups.

  2. The channels are often composed of hydrophobic $R$ group.

  3. $a$ and $b$

  4. None of these

Show answer
Correct Option: A
Explanation:

Facilitated diffusion, therefore, allows polar and charged molecules, such as carbohydrates, amino acids, nucleosides, and ions, to cross the plasma membrane. Two classes of proteins that mediate facilitated diffusion are generally distinguished.

So, the correct option 'The channels are often composed of charged or polar R groups'.

The movement of ions against the concentration gradient is

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

  1. Active transport

  2. Osmosis

  3. Diffusion

  4. All of the above

Show answer
Correct Option: A
Explanation:

Active transport is the movement of molecules across a cell membrane in the direction against their concentration gradient, i.e. moving from an area of lower concentration to an area of higher concentration. 

Osmotic theory for an active absorption of water was given by

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

  1. Thimann

  2. O. Hertwig

  3. Atkins and Priestley

  4. J. C. Bose

Show answer
Correct Option: C
Explanation:

There are two methods of water absorption active and passive. Active water absorption requires energy. Osmotic active absorption theory was advanced first by Atkins in 1916 and later on by Priestley, 1921, for the maintenance of high salt content in xylem channels.

Carrier ions like Na$^+$ facilitate the absorption of substances like 

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

  1. Fructose and some amino acids

  2. Amino acids and glucose

  3. Glucose and fatty acids

  4. Fatty acids and glycerol

Show answer
Correct Option: B
Explanation:

Absorption of glucose takes place with the help of a carrier protein that carries out the co-transport of glucose along with two sodium ions. Absorption of amino acids also takes place by a similar mechanism with the help of a sodium-dependent co-transporter. Absorption of fructose occurs by facilitated diffusion, and fatty acids and glycerol by a simple diffusion mechanism. 

So, the correct option is 'Amino acids and glucose'.

A student put five raisins each in two beakers A and B. Beaker A contained 50 ml of distilled water and beaker B had 50 ml of saturated sugar solution. After sometime, the student would observe that

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

  1. Raisins in beaker A were more swollen than those in beaker B.

  2. Raisins in beaker B were more swollen than those in beaker A.

  3. Raisins in both beaker A and B were equally swollen.

  4. Raisins in beaker A did not swell up at all.

Show answer
Correct Option: A
Explanation:

Raisins in the beaker A will swell as solution surrounding them is hypotonic in nature. Hypotonic solution contains lesser solute concentration. In such case, endosmosis will occur in which inward movement of the water molecules from the lower solute concentration to higher solute concentration through raisin covering. 
Raisins in the beaker B will shrink as solution surrounding them is hypertonic in nature. Hypertonic solution contains higher solute concentration. In such case, exosmosis will occur in which outward movement of the water molecules from the lower solute concentration to higher solute concentration through raisin covering. 

Transporting pull arise mainly from

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

  1. Roots

  2. Leaves

  3. Stems

  4. All

Show answer
Correct Option: B
Explanation:

As water is lost from the surface of the leaves due to transpiration a strong suction force is transmitted through the active mesophyll cells to the ends of the water column in the root. This is called transpiration pull. It caused the entire water column to be pulled upwards. When the rate of transpiration is very high and the rate of absorption is slow the water in the xylem elements of the leaf develops a state of tension.

So, the correct answer is B.