1/23: Cell Membrane, Membrane Transport, and Membrane Potential IV

Question 1

What is the most abundant molecule in our body?

Answer 1

Water - accounting for 60% of body weight (in Kg)

Question 2

The volume of water in the intracellular vs. extracellular spaces is ________

Answer 2

Unequal

Question 3

The osmolarity of the extracellular and intracellular space is ________

Answer 3

Equal

Question 4

What percent of the body is intracellular fluid?

Answer 4

40%
~2/3 total body water

Question 5

What makes up the ECF?

Answer 5

Blood plasma
Interstitial fluid

Question 6

What percent of the ECF is plasma and interstitial fluid?

Answer 6

Plasma - 5%
Interstitial fluid - 15%
~1/3 total body water

Question 7

The total body water is how much percent of the body weight in kg?

Answer 7

60%

Question 8

What percent of the 60% of body weight is ICF?

Answer 8

40% body weight
~2/3 total body water

Question 9

What percent of the 60% body weight is ECF?

Answer 9

20% body weight
~1/3 total body water
15% - interstitial fluid (75% ECF)
5% - plasma (25% ECF)

Question 10

What is the body water distribution in a 175 lb individual?

Answer 10

Question 11

What are two types of active transport?

Answer 11

1. Active transport with membrane proteins (most common)
2. Bulk (vesicular) transport

Question 12

How to active transporters work?

Answer 12

Transmembrane protein that moves ions and hydrophilic building blocks across the plasma membrane up a concentration (requires energy)

Question 13

What three things is the classification of active transporters dependent on?

Answer 13

1. Number of substances being transported
2. Directions substances are transported
3. Source of energy for transport

Question 14

What are the three types of active transporters based on number and direction of movement?

Answer 14

Uniporter
Symporter/cotransporter
Antiporter/countertransporter

Question 15

What is a uniporter?

Answer 15

Moves only one substance

Question 16

What is a symporter/cotransporter?

Answer 16

Moves more than one substance in the same direction

Question 17

What is an antiporter/countertransporter?

Answer 17

Moves more than one substance in different directions

Question 18

What are two types of active transporters based on source of energy?

Answer 18

1. Primary active
2. Secondary active

Question 19

What is a primary active transport process?

Answer 19

Energy comes directly from breakdown of ATP

Question 20

What is a secondary active transport process?

Answer 20

Energy released from one substance moving down a gradient is used to pump a second substance up a gradient

Question 21

What is an example of a primary active transport (ATPase pump)?

Answer 21

Sodium potassium pump

Question 22

What are the functions of the sodium potassium pump?

Answer 22

Maintain Na and K concentration differences
Electrogenic - establishes negative membrane potential

Question 23

What is outside and inside the cell in a Na-K pump?

Answer 23

Sodium outside
Potassium inside

Question 24

What are other examples of primary active transport?

Answer 24

Calcium pump
Hydrogen pump

Question 25

What are types of secondary active transport?

Answer 25

a. Cotransporters (symporters) b. Countertransporters (antiporters)

Question 26

What are secondary active transporters?

Answer 26

One substance going down a gradient and another going up

Question 27

Define each type of active transport

Answer 27

A. - moved into cell - symporter Secondary active symporter coupled to Na (coupled = providing most energy) B. - moved out of cell - symporter Secondary active symporter coupled to potassium C. Secondary active antiporter coupled to sodium

Question 28

What is vesicular transport/bulk transport?

Answer 28

Moves large substances across plasma membrane

Question 29

Is vesicular transport/bulk transport dependent on a gradient?

Answer 29

Gradient independent

Question 30

Does vesicular transport/bulk transport require energy?

Answer 30

Yes

Question 31

What are two types of vesicular transport/bulk transport?

Answer 31

1. Endocytosis 2. Exocytosis

Question 32

What is endocytosis?

Answer 32

Brings substance into cell Forms vesicle Removes membrane from plasma membrane

Question 33

What is exocytosis?

Answer 33

Removes substances from cell Vesicle fuses to membrane Adds membrane to plasma membrane

Question 34

What are three forms of endocytosis?

Answer 34

Pinocytosis Phagocytosis Receptor mediated endocytosis

Question 35

What is pinocytosis?

Answer 35

Cells drinking ECF and bringing nonspecific substances in

Question 36

What cells can do pinocytosis? and when do they do it?

Answer 36

All cells, all the time

Question 37

What cells can do phagocytosis?

Answer 37

Phagocytes only

Question 38

What is phagocytosis?

Answer 38

Foreign substances brought into cell - immune system

Question 39

What is receptor mediated endocytosis?

Answer 39

Specific substances brought into cell

Question 40

What cells can do receptor mediated endocytosis? and when do they do it?

Answer 40

All cells, all the time

Question 41

Where in the ICF are proteins the most in?

Answer 41

Plasma proteins > proteins of interstitial fluid

Question 42

Rank the number of proteins from most to least 1. Interstitial fluid 2. Intracellular Fluid 3. Plasma

Answer 42

1. ICF 2. Plasma 3. Interstitial fluid

Question 43

What type of active transport is shown here?

Answer 43

Secondary active symporter

Question 44

What type of active transport is shown here?

Answer 44

Secondary active symporter