Membranes And Ion Channels

Front 1

What is the main componant of intracellular fluid?

Back 1

K+ and proteins (low in Na+, Ca2+, and Cl-)

Front 2

Extracellular fluids have a high concentration of what ions?

Back 2

Na+ and Ca2+ (low K+)

Front 3

What are the three different volumes of extracellular fluid?

Back 3

Plasma, interstitial fluid (lymph) and transcellular fluid

Front 4

What is plasma?

Back 4

The noncellular portion of blood found in the capillaries.

Front 5

What is interstitial fluid?

Back 5

Fluid that is in constant exchange with plasma and found between cells.

Front 6

What is formed by ultrafiltration of capillary plasma?

Back 6

Interstitial fluid

Front 7

Where is transcellular fluid found?

Back 7

Closed cavities of the body such as joints, ventricals, spinal cord, cartilage and bones martixes, ect.

Front 8

What contains the apparatus for transmembrane signaling?

Back 8

plasma membrane

Front 9

What substances can cross the membrane via simple diffusion?

Back 9

Water, alcohol, O2 and CO2

Front 10

What substances move across the membrane via facilitated diffusion?

Back 10

Ions such as Na+, Ca2+, K+, Cl

Front 11

What causes the chemical driving force behind simple diffusion?

Back 11

differences in concentration

Front 12

What are 4 characteristics of simple diffusion?

Back 12

1.) low temp sensitivity 2) no saturation with increased concentration 3) sensitive to lipid soluability and molecule size 4) occurs down a concentration gradiaent

Front 13

What are two factors that cause water movement across a membrane?

Back 13

concentration gradients or hydrostatic pressure

Front 14

What is osmosis?

Back 14

water movement by simple diffusion down a concentration gradient

Front 15

What is osmotic pressure difference?

Back 15

The hydrostatic pressure that just prevents the net movement of water

Front 16

What are the 5 characteristics of facilitated diffusion?

Back 16

1) No energy used 2) saturation occurs 3) specific to certain carriers 4) competitive inhibition occurs 5) dependant on temperature

Front 17

How does active transport differ from facilitated diffusion?

Back 17

1) energy dependant 2) movement against concentration gradient

Front 18

What is the difference between primary and secondary active transport?

Back 18

Primary requires direct usage of ATP while secondary uses a second ion gradient which is established by ATP.

Front 19

The Na+/Ca2+ exchanger is an example of what?

Back 19

Secondary active transport

Front 20

The electrochemical driving force considers what factors?

Back 20

chemical concentration and charge of the ion

Front 21

What kind of channels are excitable and open/close?

Back 21

Active channels

Front 22

What type of channels stay open all the time?

Back 22

passive channels

Front 23

All ion channels exhibit this characteristic

Back 23

selective permeabilitiy

Front 24

Describe characteristics of the voltage gated K+ channel

Back 24

Contains a sensor with specific range of transmembrane voltages, an activation gate, and can exist in open an closed confirmations

Front 25

Describe Na+ and Ca2+ channels

Back 25

They are voltage activated with a voltage sensor and gate. Exists in three confirmations:open, closed, and inactivated.

Front 26

Describe receptor-activated channels

Back 26

Must be stimulated by the binding of a ligand such as ACH.

Front 27

These channels close due to inactivation and cannot open until the inactivation gate returns to its resting position

Back 27

Na+ channels and Ca2+ channels

Front 28

These channels stay open as long as they are activated

Back 28

K+ channels

Front 29

What forces cause movement of ions?

Back 29

Concentration gradients and electrical fields (electrical potential difference)