Module 4A - Membrane Transport

Question 1

Two main types of membrane transport proteins.

Answer 1

Transporters and channels

Question 2

A group of protein transporters that utilizes the electrochemical potential (membrane potential) to transport molecules across the membrane bilayer.

Answer 2

SLC transporters

Question 3

A type of protein transporter that uses the hydrolysis of ATP to move molecules across the membrane bilayer.

Answer 3

ABC transporters

Question 4

The movement of ions are dictated by the:

Answer 4

Concentration gradient

Question 5

Types of molecules that can diffuse directly to the lipid bilayer without the aid of transport proteins or channels.

Answer 5

Hydrophobic molecules/Lipid soluble molecules

Question 6

Molecules with the lowest permeability and needs the aid of transport proteins to move in and out of the cell.

Answer 6

Ions

Question 7

Factors that affect permeability

Answer 7

Size and hydrophobicity

Question 8

Proteins that transfer solutes, specific molecular species, or a class of molecules.

Answer 8

Membrane transport proteins

Question 9

Transport proteins that binds and conforms to the shape of the molecule it transports. Capable of reversible conformation changes.

Answer 9

Transporters

Question 10

Transport of molecules downhill using the difference in concentration gradient.

Answer 10

Passive transport

Question 11

Movement of uncharged molecules are based on the:

Answer 11

Concentration gradient

Question 12

This is where the movement of charge molecules across the electrochemical gradient of the cell from the extracellular matrix relies on.

Answer 12

Membrane potential

Question 13

A type of active transport that uses the energy stored in concentration gradients.

Answer 13

Coupled transport

Question 14

Active transport pump that uses the hydrolysis of ATP to move molecules against the electrochemical gradient.

Answer 14

ATP-driven pump

Question 15

Protein pumps that use the energy from light to move molecules across the membrane bilayer.

Answer 15

Light/redox-driven pumps

Question 16

A transporter protein that carries only one single solute.

Answer 16

Uniporter

Question 17

Coupled transport protein that moves a molecule and a co-transported ion towards the same direction.

Answer 17

Symporters

Question 18

Transport protein that move a molecule depending on the transport of a secondary molecule and harvests the energy stored in the electrochemical gradient.

Answer 18

Couple transporters

Question 19

Coupled transport protein that facilitates the transfer of two molecules in opposite directions.

Answer 19

Antiporters

Question 20

Channels in the lipid bilayer that facilitates the movement of water molecules.

Answer 20

Aquaporins

Question 21

The solute and binding sites are located _______ through the transport protein.

Answer 21

Midway

Question 22

Four classes of ATP-driven pumps

Answer 22

1. P-type pumps
2. ABC transporters
3. V-type pumps
4. F-type pumps

Question 23

Also known as ATP synthase, it uses the H+ gradient to synthesize ATP.

Answer 23

F-type pumps

Question 24

A type of ATP-driven pump that move small molecules with the aid ATP hydrolysis

Answer 24

ABC transporters

Question 25

Pump that moves molecules using the phosphorylation from ATP.

Answer 25

P-type pumps

Question 26

ATP-driven pump that is made from multiple different subunits

Answer 26

V-type pumps

Question 27

Intracellular storage of Ca2+ in muscle cells.

Answer 27

Sarcoplasmic reticulum

Question 28

Protein transport pump that pumps out Ca2+ outside of the cell.

Answer 28

Ca2+ ATPase (Calcium pumps)

Question 29

What is the effects of pumping Ca2+ into the cytosol?

Answer 29

Muscle contraption

Question 30

10 transmembrane α-helices are connected to what three(3) cytosolic domains.

Answer 30

1. Nucleotide-binding domain 2. Phosphorylation domain 3. Activator domain

Question 31

First found in bacteria, it contains highly conserved ATPase domains that brings together two different domains.

Answer 31

ABC transporters

Question 32

What is the importance of the sodium-potassium pump?

Answer 32

Regulates cytosolic pH levels; creating electric potential

Question 33

Connects the cytoplasm of two different cells

Answer 33

Gap junctions

Question 34

Channels that facilitate the transport of inorganic ions

Answer 34

Ion channels

Question 35

Transporter protein that is associated with antigen processing.

Answer 35

TAP transporter

Question 36

A narrow pore that allows water molecules to move rapidly and traverse the membrane in a single file.

Answer 36

Aquaporins

Question 37

Regulates the flow of ions or molecules, opening briefly and closing again in response to specific stimuli.

Answer 37

Gated ion channels

Question 38

Different types of gated channels

Answer 38

1. Voltage-gated 2. Ligand-gated (intra and extra) 3. Mechanically gated

Question 39

Gated ion channel that activates due to a change in the membrane potential and facilitates active electrogenic pumping and passive ion diffusion.

Answer 39

Voltage-gated channels

Question 40

Selectivity filter that is present in voltage-gated channels.

Answer 40

Pore helix

Question 41

Neuromuscular disorder caused by voltage-gated Na+ channels in skeletal muscle cells

Answer 41

Myotonia

Question 42

A condition that occurs when the Na+ or K+ channels in the brain dysfunctions, causing the neurons to fire more faster than normal.

Answer 42

Epilepsy

Question 43

Voltage-gated channels contains __ identical transmembrane subunits that forms a central pore through the membrane.

Answer 43

Four

Question 44

When K+ ions pass through the selectivity filter, it loses almost all of its bound __________________

Answer 44

Water molecules

Question 45

Causes the titling of K+ channels inner helices

Answer 45

Closed K+ channels

Question 46

Mechanosensitive channels that are capable of responding to mechanical forces. Found in the bacterial plasma membrane.

Answer 46

Mechanically gated ion channels

Question 47

Receives, conducts, and transmits signals

Answer 47

Neurons

Question 48

Changes in the electrical potential across the neuron’s plasma membrane.

Answer 48

Action potential/Nerve impulse

Question 49

Responsible for generating action potentials and depolarization of the plasma membrane.

Answer 49

Voltage-gated cation channel

Question 50

Photosensitive ion channels that covalently bound retinal groups.

Answer 50

Channelrhodopsins

Question 51

Increase the rate at which the axon can conduct an action potential.

Answer 51

Myelination

Question 52

Two types of glial cells that form the myelin sheets.

Answer 52

Schwann cells and oligodendrocytes

Question 53

Little leaks of neuron transmission current can leak from:

Answer 53

Axons

Question 54

Neuronal signals are transmitted at:

Answer 54

Synapses

Question 55

Ion channels and feature at fast chemical synapses

Answer 55

Ionotropic receptors

Question 56

G-protein coupled receptors that bind to all other neurotransmitter.

Answer 56

Metabotropic receptors

Question 57

neuromuscular transmission involves the sequential activation of ________ different sets of ion channels

Answer 57

Five

Question 58

Open cation channels, influx of Na+ or Ca2+; firing an action potential.

Answer 58

Excitatory neurotransmitters

Question 59

Flow of synaptic neuronal signals across the neuron.

Answer 59

Presynaptic cell – synaptic cleft – postsynaptic cell

Question 60

Gaps in the myelin sheets that aid in the rapid conduction of nerve impulses

Answer 60

Nodes of Ranvier