Question

In active transport, carrier proteins are used, which use energy in the form of ATP, to
A. Transport molecules against the concentration gradient of cell wall
B. Transport molecules along the concentration gradient of the cell membrane.
C. Transport molecules against the concentration gradient of the cell membrane.
D. Transport molecules along the concentration gradient of the cell wall.

Answer 1

Transportation is an important physiological process that occurs in all life forms. It involves the distribution of nutrients, minerals across the body of an organism.
Active transport is a process that involves the movement of molecules from its region of lower concentration to a higher concentration. During this process stored energy in the form of ATP is used.
Carrier proteins are the proteins that are present on the cell membrane that carries substances from one side of the cell to the other side.

Complete answer:
There are different types of transportation in organisms they are as follows:

Diffusion
Facilitated diffusion
Active transport
Passive transport
Active transport requires external energy i.e. ATP for the transport of molecules across the cell. The transport of molecules occurs against the concentration gradient. There are two types of active transport they are - primary active transport and secondary active transport. In the case of primary active transport, the ATP is broken down during the transportation of the molecules against the concentration gradient. The ATP powered pumps have the presence of one or more binding sites for the attachment of ATP. They are present on the cytosolic side of the cell. In the case of secondary active transport electrochemical energy is used.
Each of the given options is discussed below:
Transport molecules against the concentration gradient of cell wall- To move against the concentration gradients it requires external energy in the form of ATP. This occurs in active transport.
Transport molecules along the concentration gradient of the cell membrane. – In the case of facilitated diffusion, the molecules move along the concentration gradient through protein channels that are present on the cell membrane.
Transport molecules against the concentration gradient of the cell membrane. - The cell membrane has the presence of certain proteins called carrier proteins which helps in the transport of substances. In the case of active transport, the movement occurs against the concentration gradient with the use of ATP.
Transport molecules along the concentration gradient of cell walls- the movement of molecules from its level of high concentration to lower concentration are simple diffusion. It occurs along the concentration gradient. It does not require any external energy for its movement of molecules.
In active transport, carrier proteins are used, which use energy in the form of ATP, transport molecules against the concentration gradient of the cell membrane.
The correct answer is option C.

Note:
The cell wall is permeable to all the molecules but the cell membrane is selectively permeable that allows only certain types of molecules inside the cell.
Passive transport involves the processes like diffusion, osmosis where there is no need for any energy such as ATP for the transport of molecules.