The Cell Membrane Flashcards
List the 4 main functions the cell membrane has
1. Physical barrier
Separates inside of the cell (cytoplasm) from the outside (extracellular fluid).
2. Controls passage of materials
Entry/exit of molecules and substances
3. Senses changes
Contains receptors
4. Supports structure
Attached to microfilaments.What is currently the most accepted model for the cell membrane
Fluid mosaic model
What does fluid mean
molecules constantly moving
What does mosaic mean
made of different types of molecules
The cell membrane consists of…
a phospholipid bilayer
Cholesterol
Proteins
Is the phosphate head hydrophobic or hydrophilic
hydrophilic
Is the lipid tail hydrophobic or hydrophilic
hydrophobic
What is the location of the phosphate head
Outside of the layer
What is the location of the lipid tail
Inside of the layer
Active transport across the cell…
Uses the cells energy
Passive transport across the cell…
does not involve using the cells energy
Example processes for active transport across a cell
facilitated transport
Vascular transport
Example processes for passive transport across a cell
simple diffusion
Osmosis
Facilitated transport
What is diffusion
The process of particles spreading out results in an even distribution of gases and liquids
What is osmosis
The diffusion of a solvent through a differentially permeable membrane resulting in a balanced concentration.
what is Vesicular transport
the movement of substances across the cell membrane in membranous sacs called vesicles
what is Facilitated transport
Transport through proteins
What is the process of carrier proteins
- ) specific substance binds to a binding site
- ) protein changes shape and opens up
- ) substance is released on the opposite side
Endocytosis…
entering the cell
Exocytosis…
exiting the cell
Phagocytosis
solid particles
Pinocytosis…
liquid particles
Is Facilitated diffusion along or against the concentration gradient
along (high->low)
Is active transport along or against the concentration gradient
against (low->high)
If we increase the rate of exchange across the cell membrane (surface area) would it increase or decrease in volume (cytoplasm)?
decrease
If we increase the rate of exchange across the cell membrane would it increase or decrease in the surface area (cell membrane )?
increase
If we increase the rate of exchange across the cell membrane (surface area) would it have a higher or lower concentration gradient?
a higher concentration gradient
If we increase the rate of exchange across the cell membrane (surface area) would proteins be saturated (full) or partially occupied?
proteins are partially occupied
If we increase the rate of exchange across the cell membrane (surface area) would temperature be increasing or decreasing?
temperature would increase
