Passive or Active?
This type of transport does not require energy.
What is passive transport?
This membrane protein changes shape to move molecules across.
What is a transporter?
Molecules move passively from ___ concentration to ___ concentration.
What is high to low?
The Na⁺/K⁺ pump moves ___ Na⁺ out and ___ K⁺ in.
What is 3 Na⁺ out, 2 K⁺ in?
Ion channels are always what type of transport?
What is passive? (facilitated diffusion)
This is because they move ions down their electrochemical gradient (from high concentration to low concentration or from an area of high electrical potential to low electrical potential) and do not require the cell to expend energy.
Large polar molecules and ions usually require this type of protein to cross membranes.
What is a transporter or channel?
This membrane protein allows ions to flow rapidly without conformational change.
What is a channel?
Is inside or outside of the cell negative and which side is positive?
positive outside the cell and negative inside the cell
The Na⁺/K⁺ pump requires this energy source.
What is ATP hydrolysis?
This type of gate opens when the membrane voltage changes.
What is voltage-gated?
The transport of glucose down its concentration gradient is an example of this.
What is passive/facilitated diffusion?
Channels are always this type of transport.
What is passive?
Na⁺: [out]=145 mM, [in]=10 mM. Which way will Na⁺ move if channels are open?
Into the cell.
True or False: The Na⁺/K⁺ pump is found in both animal and plant cells.
What is False? (Almost all animal cells, not plant cells).
This type of channel opens when a ligand binds.
What is ligand-gated?
This kind of transport requires ATP hydrolysis.
What is active transport(pumps)?
Transporters can use either ___ or ___ transport.
What is passive or active?
Define “electrochemical gradient.”
The combined effect of concentration gradient and membrane potential on ion movement.
What does the Na⁺/K⁺ pump help establish in cells?
The membrane potential.
This type of channel opens when the membrane is stretched or pressured.
What is mechanically-gated?
True or False: Charged ions can diffuse freely across the lipid bilayer. What do they require?
What is False? A specialized integral membrane protein, such as an ion channel or a carrier protein
Which moves faster: a channel or a transporter? And what do they help pass through the membrane?
What is a channel? Facilitate the passage of specific, often polar, substances such as ions, sugars, amino acids, and water across the cell membrane that
If inside of a cell is negative, would positive ions be pushed in or out?
In (attracted to the negative charge).
This pump consumes about ___% of the cell’s ATP.
What is ~30%?
Channels open and close quickly, in what is called this “flickering” behavior.
What is gating?