Active Cellular Physiology

Question 1

Excitable cells use..

Answer 1

chemical and electrical gradients for rapid signalling events

Question 2

Meaning of diffusion

Answer 2

Movement of molecules from high to low concentration

Question 3

Osmosis is..

Answer 3

the movement of water across a membrane to equalise solute concentration

Question 4

The cell membrane divides out body fluid volumes into

Answer 4

intracellular and extracellular spaces

Question 5

Water concentration is dynamic on both sides of the membrane..

Answer 5

as is the concentration of solutes and ions

Question 6

Osmosis works to balance..

Answer 6

the tonicity between the intracellular and extracellular spaces

Question 7

ICF

Answer 7

Intracellular fluid

Question 8

ECF

Answer 8

Extracellular fluid

Question 9

Isotonic

Answer 9

The intracellular and extracellular fluids are in balance.

Question 10

Hypertonic

Answer 10

Water loss from extracellular fluid decreases volume and makes this solution hypertonic with respect to the intracellular fluid.

Question 11

Isotonic

Answer 11

An osmotic water shift from the intracellular fluid into the extracellular fluid restores osmotic equilibrium but decreases the intracellular volume.

Question 12

Hypotonic

Answer 12

if the solute concentration outside the cell is lower than inside the cell, and the solutes cannot cross the membrane, then that solution is hypotonic to the cell.

Question 13

Ion concentration is also

Answer 13

dynamic in both the intracellular and extracellular spaces

Question 14

Uneven distribution of molecules across the membrane creates a..

Answer 14

chemical gradient

Question 15

How is a chemical gradient created

Answer 15

Through the uneven distribution of molecules across the membrane

Question 16

Uneven distribution of charges across the membrane creates an….

Answer 16

electrical gradient

Question 17

How is an electrical gradient created

Answer 17

Uneven distribution of charges across the membrane

Question 18

Chemical and electrical gradients allow

Answer 18

rapid signalling in excitable cells

Question 19

What allows rapid signalling in excitable cells

Answer 19

Chemical and electrical gradients

Question 20

The cell membrane is semi permeable and won’t allow

Answer 20

ions through

Question 21

The moment a pathway opens,

Answer 21

the ions will rush in/out along their gradient

Question 22

The bigger the gradient,

Answer 22

the faster and stronger the signal

Question 23

Ions can move down the chemical gradients through

Answer 23

passive ion channels

Question 24

The sodium and potassium gradients are maintained by..

Answer 24

active pumps that use energy to move ions against their concentration gradient

Question 25

How are sodium and potassium gradients maintained

Answer 25

by active pumps that use energy to move ions against their concentration gradient

Question 26

At rest, the intracellualr space has..

Answer 26

more negative charge than the extracellular space, creating an electrical gradient which is the resting membrane potential

Question 26

Resting membrane potential

Answer 26

At rest, the intracellular membrane has more negative charge than the extracellular space, creating an electrical gradient.

Question 26

Excitable cells

Answer 26

Nerves, muscles

Question 26

Excitable cells use the movement..

Answer 26

of ions as a signal via depolarization

Question 26

Difference between osmosis and diffusion

Answer 26

Diffusion is the movement of molecules down a concentration gradient, while osmosis is the movement of water across a membrane to balance the tonicity on both sides.

Question 26

Ions are distributed unevenly across the cell membrane at rest to..

Answer 26

create chemical and electrical gradients

Question 27

The electrical gradient when the cell is at rest is known as..

Answer 27

the resting membrane potential

Question 28

Positive ions enter the cell during a depolarization,

Answer 28

which acts as a signalling event for excitable cells

Question 29

Positive ions are then removed during repolarization

Answer 29

to return to the resting membrane potential