lecture 2

Question 1

permeability of lipid bilayer

Answer 1

artifical bilayer is impermeable to most soluble water molecules
cell membrane uses transport proteins to transport speficic molecules (facilitated transport)

Question 2

permeable

Answer 2

simple diffusion, going from high concentration to low concentration, faster diffusion of hydrophobic/non polar molecules, faster when small

Question 3

impermeable

Answer 3

require membrane proteins for them to go across the membrane

Question 4

transmembrane transport proteins

Answer 4

create a path across the membrane, transport polar and charged molecules, they are selective, two main classes

Question 5

channel

Answer 5

no conformational changes, selective of size and electric charge, transient interactions as solute passes through

Question 6

transporters

Answer 6

selective of what fits in binding site, like lock and key, speficic binding of solute, goes through conformational changes

Question 7

simple diffusion

Answer 7

molecules just go through the membrane, needs no help

Question 8

passive

Answer 8

channel, transport mediated when with concentration gradient, no energy needed

Question 9

active transport

Answer 9

energy needed, when going against the gradient

Question 10

electrochemical gradient

Answer 10

concentration gradient+ membrane potential= elevtrochemical gradient

Question 11

electrochemical gradient

Answer 11

when there is a membrane potental

Question 12

concentration gradient

Answer 12

there is no membrane potential

Question 13

channel proteins

Answer 13

hydrophilic pore across the membrane, they are selective of ion size and charge, they are passive transport, they are faster than transporters

Question 14

ion channels

Answer 14

they are found in animals, plants, and microorganisms, gated and non gated

Question 15

non-gated ion channels

Answer 15

they are always open, major role in generating resting membrane potential in plasma membrane of animal cells

K+ leak channels

Question 16

gated ion channels

Answer 16

signal is requited for the channel to open

signal could be, mechanical stress, ligand (whether extra or intra cellular), or a change in voltage across the membrane

Question 17

transporter proteins

Answer 17

they bind to a specific solute, they go through cinformational changes

uniport, symport, antiport, p-type pump, v-type pump, ABC transporter

Question 18

uniport

Answer 18

only one solute, passive transport down the electrochemical gradient, the direction of transport is reversible

Question 19

gradient driven pump

Answer 19

1st solute goes down its gradient and created energy which allows the second solute to go against its gradient

symport and antiport

Question 20

ATP-driven pump

Answer 20

ATP hydrolysis of energy, tje solute moves against its gradient and ATP is turned to ADP

Question 21

light driven pump

Answer 21

light energy, solute moves against its gradient

Question 22

symport

Answer 22

two solutes, they move in the same direction

Na+ down its electrochemical gradient provides energy for glucose to move against its gradient, they go the same way

Question 23

antiport

Answer 23

two solutes, move in oposite direction

Na+ goes down its electrochemical gradient and provides energy for H+ to move against its electrochemical gradient in the opposite direction

Question 24

Na+ electrochemical gradient maintness

Answer 24

both symports and antiports, the continued action of the gradient driven pumps keeps an equilibrium in the Na+ gradient

Question 25

p-type pump

Answer 25

ATP driven, phosphorylated, ion transport that builds up/maintains electrochemical gradients

Na+-K+ pump
both move against their gradient
3Na out 2 K in
keeps inbalance
the Na gradient is used tp transport nutrients such as glucose into the cell and maontain pH

Question 26

ABC transporter

Answer 26

uses 2 atp to pump small molecules across cell membrane

Question 27

v-type proton pump

Answer 27

uses ATP to pump H+ into organelles to acidify the luman
uses atp rto pump H+ against electrochemical gradient

Question 28

f-type ATP synthase

Answer 28

structurally related to V-type proton pump but its the opposite, uses h+ gradients to drive the synthesis of ATP, uses electrochemical gradient to produce atp, reversibe

Question 29

transport protein processes used to regulate critical cellular processes

Answer 29

transcellular transport of glucose by transporters, work together to transfer glucose from intenstine to blood stream

Question 30

membrane potential

Answer 30

difference in electrical charge on two sides of the membrane

Question 31

generation of membrane potential animals

Answer 31

K+ leak channel, outward flow of K+

Na-K pumps, maintaines gradient of Na with low cytosolic and high cytosoluc K

cell generally balance electrical charged inside and out of the cell

Question 32

generation of membrane potential plants

Answer 32

Plasma membrane p-type pump
generates H+ electrochemical gradient`