Transport Across Cell membranes

Question 1

What are the two main types of membrane proteins that shift molecules in & out the cell?

Answer 1

1. Transporters
2. Channels

Question 2

The _______ the molecule & more ________ it is the faster it would move across the bilayer (diffuse rapidly)

Answer 2

The smaller & more nonpolar

Question 3

Small uncharged _______ molecules diffuse (move quickly) across the bilayer

Answer 3

Polar

Question 4

Differences in the concentration of inorganic ions across the cell membrane creates a ___________

Answer 4

Membrane Potential

Question 5

Membrane Potential

Answer 5

Caused by the inbalance of charge ions that create a voltage difference across the membrane

Question 6

Resting membrane potential

Answer 6

When the movement of anions & cations across the membrane is balanced

Question 7

The _________ between channels & transporters is how they choose to allow certain molecules to pass through

Answer 7

Difference

Question 8

___________ choose base on size & charge so only ions of the right size & charge can through it

Answer 8

Channels

Question 9

________ transfer only molecules or ions that fit into its specific binding site

Answer 9

Transporters

Question 10

Substances cross the membrane by either ________ or ________ transport

Answer 10

Passive or Active

Question 11

__________ & _________ allow small, hydrophilic molecules & ions to cross the cell membrane

Answer 11

Transporters & channels

Question 12

The direction of the molecules whether they move in or out the cell depends on their _________

Answer 12

Concentration

Question 13

Substances flow from _________ concentrations to _________ concentration

Answer 13

From high concentration to low concentration

Question 14

Passive Transport

Answer 14

Substance flowing from high concentrations regions to low concentration regions

Question 15

Active Transport

Answer 15

Carried out by transporters proteins called pumps where they move substance from low concentration to high concentration

Question 16

Electrochemical Gradient

Question 17

Osmosis

Answer 17

Water moving across the cell membrane down its concentration gradient (from an area of low solute concentration (high water concentration) to an area of high solute (low water concentration))

Question 18

Aquaporins

Answer 18

Are specialized channels that speed up the movement of water across the cell membrane

Question 19

Transporters are responsible for the movement of __________, _________ across the cell membrane

Answer 19

Small water soluble organic molecules & inorganic ions across the cell membrane

Question 20

___________ move a solute along its eletrochemical gradient

Answer 20

Passive transporters

Question 21

_________ actively transport a solute against its electrochmeical gradient

Answer 21

Pumps

Question 22

The _______ pump in animal cells uses energy from ATP to expel ______ & bring in K⁺

Answer 22

Na⁺

Question 23

ATP -driven Na⁺ pump

Answer 23

Is used in animal cells to remove Na⁺ out of the cell & bring in K⁺ into the cell

Question 24

ATP driven Ca²⁺ pumps in the plasma membrane & the ER membrane actively remove Ca²⁺ from the ________

Answer 24

Cytosol

Question 25

Symport

Answer 25

When the pump moves both solutes in the sam edirection across the membrane

Question 26

Antiport

Answer 26

When the pump moves the solutes in opposite directions

Question 27

Uniport

Answer 27

Transporter that move only one type of substance across the membrane

Question 28

Plants, fungi, & bacteria rely on the ____________ to import solutes into the cell

Answer 28

Electrochemical gradient of H⁺

Question 29

Channels form __________ that allow the passive movement of small, water - soluble molecules & ions in or out of the cell

Answer 29

Transmembrane pores

Question 30

What are the two characterisitcs of ion channels?

Answer 30

1. They are ion selectively where they only permit some inorganic ion to pass
2. They dont always stay open & some are gated (closed), they can switch between being open & closed

Question 31

Patch Clamp Recording

Answer 31

Provides a direct picture of how individuals ion channels behave

Question 32

Different types of gated ion channels respond to different types of stimuli when it stwiches between _________ & ________

Answer 32

Open & Closed

Question 33

Voltage - gated channel

Answer 33

The probability of being open is controlled by the membrane potential

Question 34

Ligand - gate channel

Answer 34

Opening is controlled by the binding of some molecule to the channel

Question 35

Mechanically - gated channel

Answer 35

Opening is controlled by a mechanical force applied to the channel

Question 36

Neurons

Answer 36

Recieve, integrate, & transmit signals

Question 37

Nuerons contin _______ which conducts electrical signals away from the cell body toward distant target cells

Answer 37

Axons

Question 38

Axons allows contain ________ which provides a large surface area to recieve signals from the axons of other neurons

Answer 38

Dendrites

Question 39

Action Potential

Answer 39

Carries a nerve message without weakening from one end of a neuron to the other end

Question 40

Action potential are mediated by ___________ channels

Answer 40

Voltage - gated channel

Question 41

To transmit the neuron message the electrical signal is coverted into a chemical signal celled _____________

Answer 41

Neurooontransmitter

Question 42

A chemical signal is converted into an electrical signal by ____________ ion channel at a synapse

Answer 42

Postsynoptic transmitter - gated ion channel