Transport of molecules - class-XII

Isotonic means two solutions having the same osmolarity. It allows the free movement of water across the membrane without changing the solute concentration. Hypotonic surrounding solution means a solution with less osmolarity. This means that concentration of solutes is less in the surrounding medium, than the concentration of solutes in cell sap and hypertonic surrounding solution means the concentration of solutes is more than the concentration of solutes in the cell sap.

A plant cell wall is fully permeable and it cannot regulate the entry or exit of a solution. When a plant cell is placed in a hypertonic solution it will lose water by exosmosis. This process is called plasmolysis. The protoplasm will shrink and will move inwards and away from the cell wall. As a result, the hypertonic solution will occupy the space between the plasma membrane and the cell wall. Thus the correct answer is option C.

Osmosis is the movement of water across a semi-permeable membrane. Water moving up a xylem vessel is primarily driven by transpiration pull and cohesion-tension, not osmosis.

During stomatal opening, K+ ions are actively pumped into guard cells, which requires an increase in pH (alkalinity) to facilitate the process.

If a cell is placed in hypotonic solution, water start moving into the cell by the process of endosmosis and cell become turgid.

Ephemerals are short-lived plants that complete their life cycle during a short favorable season, effectively escaping the drought period.

Similar to the previous question, movement of water between xylem elements is bulk flow, not osmosis.

The sequence is: K+ ions move into guard cells (2), which lowers the water potential, causing water to move in (4), which increases the turgor pressure (1). The pH change (3) is associated with the K+ transport.

Osmotic pressure is the minimum pressure applied to prevent the inward flow of solvent molecules from a dilute solution into the concentrated solution, where both solutions are separated by a semipermeable membrane. 

Active transport from outside to the inside of molecules across a membrane requires ATP. It is required in transferring solutes across the membrane may be through an ATPase which creates ph gradient across the membrane. Thus, the correct option is C.

In the active transport, there is a movement of some substance from low concentration to the high concentration i.e., against the concentration gradient wit the help of ATP combined with carrier molecules.

All mineral salts are present in soil as charged ions adsorbed to clay particles. The minerals are absorbed in charged forms and not in uncharged forms through the exchange process. Thus, the correct answer is option A.

Glucose and amino acids are absorbed against their concentration gradients in the small intestine. This process requires energy in the form of ATP, which characterizes active transport.

Active Transport uses energy to pump molecules against a concentration gradient and is carried out by membrane proteins.

In cellular biology, active transport is the movement of molecules across a membrane from a region of their lower concentration to a region of their higher concentration—against the concentration gradient. Active transport requires cellular energy to achieve this movement. There are two types of active transport: primary active transport that uses ATP, and secondary active transport that uses an electrochemical gradient. An example of active transport in human physiology is the uptake of glucose in the intestines. So substances like glucose, amino acids, sodium ions in filtrate are reabsorbed by active transport.

Minerals are absorbed from the soil in the form of ions. Absorption of minerals and water are two different processes but the  pathway is same. Mineral ions cannot be absorbed by osmosis or diffusion because the concentration is low. So the root hair cells have carrier molecules on their surface which pick the ions and move against the concentration gradient. Since the movement is against the concentration gradient then ATP will be required. So The absorption of ion is a Active process. 

The sodium-potassium pump is a specialized mechanism to transport proteins using energy. The process of moving sodium and potassium ions across the cell membrane is an active transport as it involves the hydrolysis of ATP. The hydrolysis of ATP molecule provides the necessary energy for the transport of molecules across the membrane. The action involves an enzyme known as Na+/K+-ATPase.

Lines of stomates (shown by the orange colour of the guard cells) lie along the flanks describe the status and movement of water in plants, soil and the atmosphere. This internal hydrostatic pressure (also called turgor pressure) is typically 0.5 away from the cell wall, and solution with small molecular weight solutes. 

• After dipping into water wilted vegetable regain their size, as water travells through a network of veins through out the plant and cell are hydrated and refirm their size. by a process called osmosis .
• Leaves turn yellow or red when they falls , in fallpalnt breakdown and reabsorb chlorophyll, letting the colours of other pigments show through , hence colour changes.
• When vegitables are wilted due to  dehydration, their size decreases due to loss of water.
  

Sodium-potassium pump is important to produce action potential by nerve cells. As it transport of three Na+ to the outside of the cell and the transport of two K+ ions to the inside. This changes the membrane potential on the inside, making the inside of the cell more negative or hyperpolarized, which leads to forward movement of electric impulse

 It is called water absorption 'through roots', rather 'by' roots. It occurs in rapidly transpiring plants during the daytime, because of the opening of stomata and the atmospheric conditions. The force for absorption of water is created at the leaf end i.e. the transpiration pull.

There are two types of absorption mechanisms i.e., active and passive transport. Active transport is the movement of solute or solvent molecules against the concentration gradient. It requires the expenditure of energy in the form of ATP. Thus, the correct answer is option B.

In active transport, substances move against a concentration gradient across a cell membrane. Hence energy is required. The energy available in the body in the form of ATP is used to move this substance across the cell membrane. Thus the correct answer is option C.

Active transport is defined as the movement of molecules or ions across a cell membrane against their concentration or electrochemical gradient, requiring cellular energy.

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.

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

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.

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.

• 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 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.

The Na+/K+ pump uses ATP to move sodium ions out of the cell and potassium ions into the cell, both against their respective concentration gradients. This is a classic example of primary active transport.

• 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'.

Active transport is a physiological or biological process mediated by membrane proteins, not a simple chemical reaction. It relies on ATP, uses carrier proteins, and is highly sensitive to metabolic inhibitors and enzymes that regulate these proteins.

• Active transport can be defined as the movement of molecules or ions across a plasma membrane from a region of lower concentration (of molecules or ions) to a region of higher concentration, against the concentration gradient. 
• For this cellular energy is required which is available in the form of ATP molecule and enzymes.
• So, the correct answer is 'All of the above'.

Active transport is highly sensitive to metabolic inhibitors because it depends on ATP production. If ATP synthesis is inhibited, active transport stops.

Absorption of water takes place by both active and passive absorption.
Water, as per some theory, is absorbed against the concentration gradient. This type of absorption is termed active absorption where the movement is against the concentration gradient and requires energy in the form of ATP.

The monosaccharides glucose and galactose are transported into the epithelial cells by common protein carriers via secondary active transport I.e  by co-transport with sodium ions. The monosaccharides leave these cells via facilitated diffusion and enter the capillaries through intercellular clefts.

• Active transport is the transport where the direct expenditure of energy takes place and the molecules move against the gradient which is from lower concentration to the higher concentration.
• Passive absorption is the absorption which takes place without expenditure of energy. The water molecules move from higher concentration to the lower concentration which is towards the gradient. 
• In diffusion, the ions or molecules randomly diffuses the semipermeable membrane along the concentration gradient.
• Osmosis is the process of diffusion of molecules from the region of higher concentration to the lower concentration through a semipermeable membrane. 

Carrier proteins are those which facilitate diffusion of molecules across the cell membrane, they allow movement of molecules in and out of the cells against the concentration gradient. Active transport requires carrier proteins also called as pumps. They need ATP energy because the transport is uphill, against the concentration gradient.

The sodium-potassium pump in a cell membrane works via active transport. It uses a carrier protein and utilizes ATP molecules. It transports the sodium ions to the extracellular space, increasing their concentration there and in turn moves potassium ions inside the cell. This pump moves three potassium ions inside the cell for every two sodium ions moved outside.

Active transport is usually associated with accumulating high concentrations of molecules that the cell needs such as ions, glucose, and amino acids. The processes use chemical energy for this, it comes from the hydrolysis of the ATP molecule which maintains the electrochemical gradient. Hence ATP is required for active transport. 

ATP acts as a solute pump, it's an enzyme that pumps out sodium and pumping potassium in the cells, exports three sodium, and two potassium ions. It is an active transport leading to the hydrolysis of ATP molecules to provide the required energy.

An input of energy is required in the process of active transport as it involves the movement of ions or molecules across a cell membrane from low to high concentration. The movement requires energy to maintain the electrochemical gradient.

The movement of ions or molecules against a concentration gradient (from lower to higher concentration) across a cell membrane with the utilization of energy is known as active transport. Active transport needs cellular energy which is given by ATP hydrolysis.

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

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.

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'.

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.

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. 

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.

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. 

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. 

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.

(A) Osmosis is the movement of the solute molecule from lower concentration to higher concentration through a semi-permeable membrane.