Membrane Transport Mechanisms in Cells

Questions and Answers

It involves a change in the shape of the transport protein.

It moves solutes against their concentration gradient.

It allows solutes to flow down their concentration gradients. (correct)

It requires energy in the form of ATP.

It does not require specific transport proteins.

Solutes move freely in both directions without energy.

Active transport increases entropy in the system.

It moves molecules from lower to higher concentration areas. (correct)

It decreases the concentration gradient of solutes.

It helps maintain the cell membrane's fluidity.

It is converted to glucose to provide energy for transport.

It activates transport proteins by donating a phosphate group. (correct)

It is selectively permeable, allowing specific substances to pass. Signup and view all the answers

Passive transport proteins do not require energy. Signup and view all the answers

It changes shape again and reverts to its original state. Signup and view all the answers

Passive transport. Signup and view all the answers

The difference in solute concentration across a membrane. Signup and view all the answers

Study Notes

Essential for cell growth and normal function through nutrient uptake from the environment.
Specificity in uptake mechanisms ensures that only necessary substances are acquired, avoiding harmful compounds.
Transport systems are integrated within the cytoplasmic membrane, which is selectively permeable.

Diffusion across lipid bilayer: Involves the movement of small or nonpolar molecules directly through the membrane.
Passive Transport:
- Involves solute flow via passive transport proteins.
- Operates along concentration gradients (high to low concentration).
- Does not require cellular energy for function.
- Allows bidirectional movement of solutes.
Active Transport:
- Moves molecules from an area of lower concentration to higher concentration, against the concentration gradient.
- Requires activation of transport proteins and consumes energy, primarily in the form of ATP.
- ATP donates a phosphate group, which alters the shape and affinity of the transport protein for the solute.
- After the solute is released on the opposite side of the membrane, the phosphate group is removed, allowing the protein to return to its original state.