Quiz - CH 05 Resting Membrane Potential and Local Control

Which of the following is not true of carrier proteins?

A) Carrier proteins bind to a molecule and then release it on the opposite side of the cell membrane.

B) Carrier proteins can become saturated when the concentration of ligand is too high.

C) Carrier proteins may be used for either active transport or facilitated diffusion.

D) Carrier proteins form “tunnels” or channels through which ions or small molecules can diffuse across the cell membrane.

Carrier proteins form “tunnels” or channels through which ions or small molecules can diffuse across the cell membrane.

A penetrating solute:

Note 1: you may select some, all, or none of the options below.

A) may cause the osmolarity inside a cell to increase..

B) can normally be ignored when predicting the tonicity of a solution.

C) is able to diffuse across the plasma membrane and into a cell.

D) dissociates into two more more particles, each of which contribute to the osmolary of the solution.

may cause the osmolarity inside a cell to increase..

can normally be ignored when predciting the tonicity of a solution.

 

is able to diffuse across the plasma membrane and into a cell.

A cell is able to take up specific molecules that are too large to pass through a carrier protein or channel protein by:

A) phagocytosis

B) receptor-mediated endocytosis

C) exocytosis

D) pinocytosis

receptor-mediated endocytosis

The body's extra cellular fluid (ECF) consists of fluid found in which of the following locations?

Note: you may select some, all, or none of the options below.

A) cells (i.e. the intracellular fluid)

B) lumen of hollow organs

C) interstitial fluid (a.k.a. tissue fluid)

D) blood plasma

interstitial fluid (a.k.a. tissue fluid)

blood plasma

The SGLUT transporter moves both glucose and Na⁺into a cell even though the concentration of glucose is higher inside the cell than outside the cell (i.e. glucose is being moved across the membrane against its concentration gradient).  This is most accurately described as:

A) facilitated diffusion

B) secondary active transport

C) simple diffusion

D) active transport

secondary active transport

The movement of solvent* down its concentration gradient across a semi-permeable** membrane is called __________.

* In physiology, the solvent is always water.

** In physiology, the "semi-permeable membrane" is often the plasma membrane.

A) tonicity

B) osmosis

C) diffusion

D) osmolarity

E) facilitated diffusion

osmosis

Match each description to the correct type of ion channel below.

1) Opens or closes when a physical stimulus (e.g. tension or compression) pushes on, pulls on, or otherwise changes the shape of this type of channel.

2) Opens or closes when a specific ligand binds to to this type of channel.

3) Opens or closes when the voltage difference between the space outside and inside the plasma membrane changes

1) mechanically - gated ion channels

2)chemically - gated ion channels

3) voltage - gated ion channels

Select each of the following statements below that are true of diffusion.

Note: you may select some, all, or none of the options below.

A) Molecules move from an area where they are highly concentrated to an area where they are less concentrated.

B) Occurs more slowly as temperature increases.

C) Requires a partition (e.g. the plasma membrane)

D) Occurs rapidly over short (microscopic) distances but very slowly over long (macroscopic) distances.

E) Continues until the concentration of the molecule is uniform (i.g. until the concentration is approximately equal everywhere in the container).

F) Occurs more slowly as the molecular weight of the molecule increases.

G) Requires ATP (either directly or indirectly)

Molecules move from an area where they are highly concentrated to an area where they are less concentrated.

Occurs rapidly over short (microscopic) distances but very slowly over long (macroscopic) distances.

Continues until the concentration of the molecule is uniform (i.g. until the concentration is approximately equal everywhere in the container).

Occurs more slowly as the molecular weight of the molecule increases.

Which of the following is not a way that diffusion across a biological membrane is different from simple diffusion?

A) Hydrophilic molecules normally require channels or carrier proteins to cross biological membranes.

B) Diffusion across a biological membrane always requires energy.

C)The ability of a molecule to diffuse across biological membranes depends on how lipid-soluble (i.e. hydrophobic) it is.

D) Diffusion across a biological membrane depends on the surface area of the membrane.

Diffusion across a biological membrane always requires energy.

If a substance moves across an epithelium by passing between adjacent epithelial cells it is best described as:

A) secondary active transport

B) transcellular transport

C)transcytosis

D) the paracellular pathway

the paracellular pathway