Proteins and Permeability

Question 1

what are the six major functions of membrane protein?

Answer 1

1) transport
2) Enzymatic activity
3) Cell to cell recognition
4) Attachment to cytoskeleton & Extra-cellular matrix
5) Single transduction
6) Intracellular joining

Question 2

What moelcules have some permeability?

Answer 2

Some permeability to water molecules and small uncharged molecules like carbon dioxide and oxygen

Question 3

What molecules aren’t permeable?

Answer 3

ions, K+,CA 2+,NA +, Cl-, HCO3-, small hydrophilic molecules, macromolecules (protein/RNA) and sugar (fructose and glucose)

Question 4

What is diffusion?

Answer 4

Due to random motion over time, molecules become more equally distributed, no energy is required. It eliminates a con. gradient so molecules can cross

Question 5

What is osmosis?

Answer 5

Diffusion of water through a selectively permeable membrane from an area of low con. into an aqueous compartment containing absolute at a higher concentration (across)

Question 6

When does osmosis occur?

Answer 6

It occurs when a solute cannot cross the cell membrane, so the water moves instead

Question 7

Passive transportation

Answer 7

moves from an area with a high con, to an area with low con.

Question 8

What is facilitated diffusion?

Answer 8

Passive transport aided by proteins, down the con. gradient via transport protein

Question 9

What is active transport?

Answer 9

Sodium and potassium pump moves ions against their con. gradient ( requires energy)
Lower con –> to a higher con.
USES ATP

Question 10

Co transport?

Answer 10

sodium and glucose ions move into the cell through a co-transporter protein glucose with and sodium against

Question 11

Osmotica and osmolarity

Answer 11

Glucose stays the same, ions break up, if you have two times then add together

Question 12

Questions to ask doing osmolarity Qs

Answer 12

1) can the solute cross the membrane w/passive diffusion (it doesn’t count)
2) osmosis
3) When a solute dissolves, does a molecule stay together or split into ions?

Question 13

Osmolarity =?

Answer 13

(osm/L)= molar con X no. moles or ions in solution

Question 14

What is the tonicity?

Answer 14

The ability of a solution to cause a cell to gain/loose water

Question 15

Define isotonic?

Answer 15

Solution concentration is the same as the inside of the cell, no net water movement across the plasma membrane.

Question 16

Define hypertonic?

Answer 16

Solution concentration is greater than that inside the cell; the cell loses water (shrivel)

Question 17

Define hypotonic?

Answer 17

solution concentration is less than that inside of the cell; the cell gains water (lysed)

Question 18

Hypotonic in plants?

Answer 18

Turgid

Question 19

Isotonic in plants?

Answer 19

Flaccid

Question 20

Hypertonic in plants

Answer 20

Plasmolysed

Question 21

1 M =?

Answer 21

1000 mM