Membrane Transport Flashcards
Passive Transport
Requires no input of energy
What are the types of passive transport?
Diffusion and Osmosis
Diffusion
Movement of molecules from high to low concentration
What are factors that effect the rate of diffusion?
- Temperature = warmer temps molecules move faster
- Pressure = higher pressure makes molecules since there is less space
-Size of Molecule = smaller molecules move faster - Concentration gradient = The greater the difference the faster the rate of diffusion
Osmosis
Diffusion of water
The movement of water molecules from high to low concentration
How many osmotic conditions are there and what are they?
3 osmotic conditions
Isotonic, Hypertonic, Hypotonic
Isotonic
The concentration of dissolved solutes is equal in and out of the cell. The water concentration is the same. The cell stays the same size
example of an isotonic solution
The saline solution given to patients. 0.7% NaCl is isotonic to cells
Hypertonic
The concentration of solutes is greater outside the cell than inside. There is a greater concentration of water in the cell.
What does Crenation mean?
When the cell lose water and shrink
Give an example of a Hypertonic situation
The salting of food for preservation. When vegetation is killed due to the salting of roads.
Hypotonic
The concentration of solutes is less outside the cell than inside. The concentration of water is less inside the cell. Water will enter the cell, the cell will increase in size.
What does cytolysis mean?
When a cell bursts because it is left as hypotonic for too long. When red blood cells are burst its called hemolysis.
Give an example of a hypotonic solution.
misting produce in markets so the plant vacuoles fill with water and push against the cell wall - turgor pressure.
Facilitated Diffusion
The movement of molecules that are charged or too large to fit through the plasma membrane - must be transported using carrier proteins (integral proteins)
Example of facilitated Diffusion
water through aquaporins; glucose
What molecules can pass through the plasma membrane easily?
Lipids, Oxygen, and Carbon Dioxide
Active Transport
Process of materials passing through the plasma membrane but requires energy. Two types are solute pumping and bulk transport.
Solute Pumping
Moves molecules against the concentration gradient (high to low)
Examples of solute pumping
ex. sodium/potassium pump - important in carrying nerve impulses
- sodium is pumped out of the cell from low to high concentration using energy provided by ATP while K+ is pumped into the cells against the concentration gradient
- electrical gradient formed by the difference of charges from the inside and outside of the cell is created by what carries nerve impulses
Ex. stores extra glucose as glycogen
-the glucose must be brought into the liver against concentration gradient
Bulk Transport
Molecules too large to fit in the cell are moved in and out. There are two major types: Endocytosis and Exocytosis
Exocytosis
a vesicle containing substances moves to the cell membrane and joins it to release the contents
Endocytosis
Brings materials into the cell. There are two types which are pinocytosis and phagocytosis
Pinocytosis
Cell drinking, when cells take in liquids, anything that has a charge