Membrane Transport+Nerve cell signaling

Question 1

What are the substances that can freely diffuse through membranes?

Answer 1

Small hydrophobic molecules
small uncharged polar molecules
these done NEED a helper protein to cross, they may still have one

Question 2

What are the types of transport proteins?

Answer 2

Passive transporters
-Carriers (moves something that isnt an ion)
-Channels (used for water - aquaporins, and Ions-gated channels)

Active transporters
-Direct primary pumps (not common, only used for ions, use energy from ATP)
-Secondary indirect co-transporter (Couples the movement of an ion down its ECG to pay for the movement of a solute against its ECG)

Question 3

What are the 3 types of Ion Gated channels?

Answer 3

Ligand gating -
voltage gating -
stretch gating -

Question 4

what are the 4 components of a neuron and their functions?

Answer 4

Soma - The body, site of housekeeping functions

Axon - propagates nerve impulses (action potentials) & serves as highway to transport materials between soma and terminals.

Dendrites - the antennae of the cell. Fingers extending from the Soma. hey are covered with synapses studded with receptors for
neurotransmitters

Terminals - Site of Neurotransmitter release

Question 5

Give an example of a Passive carrier

Answer 5

The carrier protein bind to the molecules to be transferred that eventually triggers a change in its shape. Then, based on the concentration gradient, the molecule moves across the membrane.
An example of carrier-mediated transport is a group of carrier proteins called glucose transport proteins, or GLUTs, which transport glucose and other hexose sugars through plasma membranes within the body

Question 6

give an example of a passive channel

Answer 6

There are Gated and non gated channels. The passage created by both domains prevents the polar molecules from coming in contact with the non-polar central layer of the membrane.
An example of channel-mediated transport is the passage of water through aquaporins.

Question 7

give an example of an active pump

Answer 7

It’s the transport of a single molecule across the membrane against its electrochemical gradient by using ATP as energy. An example is the plasma membrane sodium-potassium pump (Na+ - K+ -ATPase).

Question 8

give an example of an active co-transporter

Answer 8

It involves coupling the transport of one molecule with another. The energy-dependent transfer of an ion (Na+, K+, or H+) generates an electrochemical gradient of the ion across the membrane. This ion gradient is coupled to the movement of solutes on the same side or opposite side of the membrane.