Biological membranes Flashcards
This type of protein passes all the way through the membrane. They are often channels or receptors
Transmembrane proteins
This type of protein is found only on the outside or inside of the membrane
Embedded
This type of protein is bound to the outer (peripheral) membrane through electrostatic interactions. It is most often attached to lipid rafts or transmembrane proteins
Peripheral
This type of junction allows for direct cell-to-cell communication. It’s formed from connexins, which create like pores that essentially act as channels between the two cells
Gap junctions (connexons)
This type of junction prevent solutes from leaking into the intercellular space. They act as a physical link and form a single layer of tissue that adhere tight enough that things cannot leak out of the cells. Examples include the blood/brain barrier
Tight junctions
These form when cells need to communicate with on another through proximity. Example include gap and tight
Cell-to-cell junctions
Phospholipids are found in ___ concentration within the membrane while sphingolipids are found in ___ concentration
High
Low
Phospholipids have an easier time moving ____ through the membrane than ____
Laterally
Vertically
Found on the membrane, these act as attachment points for other molecules. They may have peripheral proteins attached to them as well
Lipid rafts
This type of endocytosis involves fluids and dissolved particles
Pinocytosis
This type of endocytosis involves large solids like bacteria
Phagocytosis
A cell is ____ if water moves into the cell because the intracellular solute concentration is higher inside than outside
Hypotonic
(the cell swells to form an ‘O’ like hypOtonic)
A cell is ____ if water moves out of the cell because the intracellular solute concentration is higher outside than inside
Hypertonic (Cell shrivels)
A cell is ____ if [solute] is the same inside and out, so water moves back and forth freely
Isotonic
This is the type of pressure that has to be applied from the solution side to prevent an influx of water. Occurs between a solution and pure water that are connected by a semipermeable membrane
Osmotic pressure
This factor tells you the number of particles a compound dissolves into when it’s in solution
Van’t Hoff factor
This type of diffusion involves particles moving across the membrane without the help of channels or carriers. These particles are normally small, and they also go down their concentration gradient
Simple diffusion
This type of diffusion occurs when large or impermeable particles (like those that are very polar) are unable to cross the membrane by themselves. They must rely on channels or carriers, but don’t require energy to cross the membrane
Facilitated diffusion
How do channels work to allow particles into and out of the cell?
They can be open or closed, but when they’re open, particles are simply allowed to pass through them and flow to the other side
How do carriers work to allow particles into and out of the cell?
Carriers are only open from one side of the membrane at a time. When the particle binds, the carrier spins and releases the particle on the other side
These type of channels allow the cell to maintain resting membrane potential
Leak channels, like Na+/K+ ATPase
Na+/K+ ATPase maintains ___ [Na+] and ___ [K+] intracellularly
Low sodium
High potassium
The _____ mitochondrial membrane is very permeable and has large pores while the ___ membrane has restricted permeability and cristae
Outer
Inner
