Transport Proteins and Cell Membranes

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What happens to cells without cell walls in a hypertonic solution?

They remain unaffected.

They divide rapidly.

They gain water and swell.

They lose water and shrivel. (correct)

What is the primary function of transport proteins in facilitated diffusion?

To synthesize molecules inside the cell.

To actively pump molecules against their concentration gradient.

To degrade molecules outside the cell.

To speed the passive movement of molecules across the plasma membrane. (correct)

What type of protein allows specific ions to cross the membrane?

Carrier proteins

Signal proteins

Receptor proteins

Channel proteins (correct)

What is the effect of a hypotonic solution on cells without cell walls?

They gain water and swell. Signup and view all the answers

What triggers the opening of gated channels in nerve cells?

Electrical stimulus Signup and view all the answers

What is the net direction of water diffusion in a hypertonic solution?

From the inside of the cell to the surrounding solution Signup and view all the answers

What is the primary purpose of transport proteins in a cell membrane?

To move specific substances across the membrane Signup and view all the answers

What is the driving force behind the movement of particles during passive transport?

Concentration gradient of the substance Signup and view all the answers

What is the result of a substance diffusing down its concentration gradient?

It spreads out evenly into the available space Signup and view all the answers

What is the characteristic of a membrane that allows certain substances to pass through while restricting others?

Selective permeability Signup and view all the answers

What is the term for the movement of particles from an area of higher concentration to an area of lower concentration?

Diffusion Signup and view all the answers

What is the state in which the number of molecules crossing the membrane in one direction is equal to the number of molecules crossing in the other direction?

Dynamic equilibrium Signup and view all the answers

What is the characteristic of facilitated diffusion in terms of energy requirement?

It does not require any energy input Signup and view all the answers

What is the direction of solute movement in facilitated diffusion?

Down their concentration gradients Signup and view all the answers

What is the role of carrier proteins in facilitated diffusion?

To move substances down their concentration gradients Signup and view all the answers

What is the effect of facilitated diffusion on the solute concentration inside the cell?

It has no effect on the solute concentration Signup and view all the answers

What is the relationship between the binding and release of the transported molecule and the shape change of carrier proteins?

The binding and release triggers a shape change Signup and view all the answers

What is the difference between facilitated diffusion and active transport in terms of energy requirement?

Active transport requires more energy than facilitated diffusion Signup and view all the answers