Barrier Breakdown
These two molecules are the main components of cell membranes.
What are phospholipids and proteins?
Small polar molecules like O₂ and CO₂ enter cells through this process.
What is simple diffusion?
A hypertonic solution has this relative solute concentration.
What is higher?
The process of moving large molecules into the cell using vesicles.
What is endocytosis?
Oxygen moves quickly across membranes, but glucose cannot. Why?
What is glucose needs a transport protein?
The head of a phospholipid is water-loving, meaning it is this.
What is hydrophilic?
The movement of molecules from high to low concentration without energy is called this.
What is passive transport?
A hypotonic solution has this relative solute concentration compared to the cell.
What is lower?
The process of moving large molecules out of the cell in vesicles.
What is exocytosis?
To increase membrane fluidity at low temperatures, cells increase this type of fatty acid.
What are unsaturated fatty acids?
The cholesterol associated with membranes helps do this at body temperature.
What is stabilize the membrane?
The sodium-potassium pump moves 3 Na⁺ out and 2 K⁺ in, powered by this.
What is ATP?
An isotonic solution has this effect on a cell.
What is no change?
Endocytosis and exocytosis require this.
What is energy (ATP)?
The inability of ions like Na⁺ or H⁺ to cross membranes is due to this property of the bilayer.
What is the hydrophobic core?
The “fluid mosaic model” includes proteins, lipids, carbohydrates, and this stabilizing molecule.
What is cholesterol?
In coupled transport, the downhill movement of one molecule powers this kind of transport for another.
What is active transport?
In this type of solution, a cell swells because water enters.
What is hypotonic?
A vesicle fuses with the plasma membrane to release its contents in this process.
What is exocytosis?
This process moves molecules with the gradient directly through the bilayer, requiring no protein.
What is simple diffusion?
This type of protein spans the entire hydrophobic core of the bilayer.
What is an integral protein?
Molecules like glucose that need a protein channel move by this type of diffusion.
What is facilitated diffusion?
In this type of solution, a cell shrinks because water leaves.
What is hypertonic?
Large molecules transported by endocytosis or exocytosis are first enclosed in these.
What are membrane-bound vesicles?
The sodium-potassium pump is an example of this type of transport.
What is active transport?