How does active transport differ from passive

transport?
1. Molecules move down a concentration
gradient in active transport.
2. Carrier proteins are used only in active
transport.
3. Energy is required only in active transport.
4. Energy is required only in passive transport

Unfortunately, Jiskha doesn't have a regular biology tutor.

i believe the answer is #1

It is not #1. That is a definition of diffusion.

oh my bad. sorry. biology was always tough for me

The answer would be 3.

1.D

2.A
3.D
4.B
5.B
100% trust me ^~^ ^_^

1. D

2. A
3. D
4. B
5. B
100% trust me I just took the test

thx ^_^

Active transport and passive transport are two different mechanisms by which molecules move across a cell membrane. Let's go through each statement to understand how active transport differs from passive transport.

1. Molecules move down a concentration gradient in active transport.
In passive transport, molecules move along or down their concentration gradient, meaning they move from an area of higher concentration to an area of lower concentration. Examples of passive transport include diffusion and osmosis. On the other hand, in active transport, molecules are moved against their concentration gradient, meaning they move from an area of lower concentration to an area of higher concentration. This requires energy input.

2. Carrier proteins are used only in active transport.
Carrier proteins are involved in both active and passive transport. In passive transport, carrier proteins facilitate the movement of molecules across the cell membrane without requiring energy. In active transport, carrier proteins are also used to transport molecules, but the process requires energy to move substances against their concentration gradient.

3. Energy is required only in active transport.
This statement is correct. Active transport processes require energy in the form of ATP (adenosine triphosphate) to move molecules against their concentration gradient. The energy is used to change the conformation of carrier proteins, allowing them to pump substances across the cell membrane.

4. Energy is required only in passive transport.
This statement is incorrect. Passive transport processes do not require energy. Molecules move along their concentration gradient without the need for metabolic energy. Examples of passive transport include simple diffusion, facilitated diffusion (which involves the use of channel proteins), and osmosis (the diffusion of water).

In summary, active transport differs from passive transport because it moves molecules against their concentration gradient, requires energy, and uses carrier proteins that undergo conformational changes. Passive transport, on the other hand, moves molecules down their concentration gradient, does not require energy, and may use carrier proteins or channel proteins.