Physiology chapter 2-Unassisted membrane transport Flashcards Preview

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Flashcards in Physiology chapter 2-Unassisted membrane transport Deck (14):
1

Molecules that can penetrate the plasma membrane on their own do so by which two forces?

Diffusion down a concentration gradient and movement along an electrical gradient.

2

What is diffusion?

Uniform spreading out of molecules along a concentration gradient.

3

What is a concentration gradient (chemical gradient)?

Difference in concentration of a molecule that allows for diffusion with a semi-permeable membrane.

4

What is net diffusion?

Total diffusion from both a concentration gradient and electrical gradient.

5

What is steady state, in regards to diffusion?

When diffusion rates of molecules are even in both directions.

6

What is an electrical gradient?

A difference in charge between two adjacent areas that promotes movement of ions toward the area of opposite charge.

7

What is osmosis?

The diffusion of water across a permeable membrane. Water goes toward an area of higher solute concentration.

8

What are aquaporins?

Channels used for the passage of water along a concentration gradient.

9

What is tonicity?

The effect a solution has on cell volume. This is determined by the concentration of non-penetrating solutes in solution.

10

What is an isotonic solution?

Solution with an equal concentration of non-penetrating solutes as that in the cell.

11

What is a hypotonic solution?

Solution with a lower concentration of non-penetrating solutes as that in the cell.

12

What is a hypertonic solution?

Solution with a higher concentration of non-penetrating solutes as that in the cell.

13

What is the result of a cell being in a hypotonic solution?

Cell swells. Water enters.

14

What is the result of a cell being in a hypertonic solution?

Cell shrinks. water leaves.