Cytoskeleton
This cytoskeletal fiber is the smallest and is made from the protein actin.
microfilaments (actin filaments)
This type of junction forms a seal between neighboring animal cells and prevents substances from passing between them.
What are tight junctions
This molecule makes up most of the basic structure of the plasma membrane.
What are phospholipids
The movement of molecules from an area of high concentration to an area of low concentration is called this.
What is diffusion
This molecule provides the energy used by the sodium-potassium pump.
What is ATP
These cytoskeletal fibers are made of tubulin and are the largest of the three major cytoskeletal elements.
microtubules
These junctions allow ions and small molecules to pass directly from one animal cell to another.
What are gap junctions
The "fluid" part of the fluid mosaic model refers to the ability of these molecules and many membrane proteins to move within the membrane.
What are lipids
The diffusion of water across a selectively permeable membrane is called this.
What is osmosis
During one cycle, the sodium-potassium pump moves this many sodium ions out of the cell.
What is 3 Na⁺?
These cytoskeletal fibers provide strength and help cells resist being stretched or pulled apart.
intermediate filaments
These junctions help hold animal cells together and allow tissues to withstand mechanical stress.
What are desmosomes
This molecule is located among phospholipids and helps regulate membrane fluidity.
What is cholesterol
Oxygen crosses directly through the phospholipid bilayer from high to low concentration. This is an example of this type of transport.
What is simple diffusion
During one cycle, the sodium-potassium pump moves this many potassium ions into the cell.
What is 2 K⁺
These two motor proteins move cargo along microtubules using energy from ATP.
kinesin and dynein
These structures connect neighboring plant cells and allow materials to pass directly between them.
What are plasmodesmata
A membrane protein that spans or is embedded within the phospholipid bilayer is called this.
What is an integral membrane protein
Glucose moves from high to low concentration through a membrane protein without using ATP. This is called this.
facilitated diffusion
A cell uses the movement of one substance down its concentration gradient to drive another substance against its gradient. This is called this type of transport.
What is coupled transport
A vesicle needs to travel from one part of the cell to another. This cytoskeletal element provides the "track" that the motor protein travels along.
microtubules
A tissue experiences a lot of pulling and stretching. Which type of cell junction would be especially important for keeping the cells attached?
What are desmosomes
Free points
Free points
This type of transport requires energy because substances are moved against their concentration gradient.
Answer: What is active transport?
A cell releases a large protein outside the cell by fusing a vesicle with the plasma membrane. This process is called this.
What is exocytosis