Plasma Membrane
Components of Plasma Membrane
- Phospholipid bilayer separates both sides of the membrane
- Cholestrol
- Links fatty acids of the phospholipids
- Stabilizes and strenghthens
- Makes plasma membrane more flexible and less permeable to water soluble substances
Phospholipid Molecule
Head
- Consists of phosphate ion
- Hydrophilic
- Can dissolve in water
- Polar
Tail
- Consists of lipid
- Hydrophobic
- Can't dissolve in water
- Non-Polar
Movement
Passive Transport-Simple Diffusion
-Osmosis
-Facilitated Diffusion
-Without using energy
-High concentration to low concentration
Active Transport- Using Energy
- Low concentration to high concentration
Simple Diffusion
Meaning-Movement of the molecules from the region of high concentration to low concentration
until equilibrium is achieve
There are only two molecules that can pass hydrophobic region is known as:
1.Hydrophobic molecules such as:
-Steroid
-Vitamin A,D,E and K
2.Small and uncharged molecules
-Oxygen
-Carbon dioxide
Osmosis
Meaning-Movement of water molecules from a region of high concentration to a region low concentration
-Only H2O molecules from solution can pass through the semi permeable membrane
Facilitated Diffusion
Type of molecules which pass through:
1. Pore protein- Na+ , K+
2.Carrier protein - Glucose , Amino acids
Meaning-It transports of molecules or ion to region from high concentration to region low concentration without using energy
1.Glucose from outside will attach at carrier protein
2.It attach will causes the carrier protein change it shape
3.The glucose will dettach and it transported into the cell without using energy
Active Transport
Meaning-It transports from region low concentration to region high concentration and using energy with help of carrier protein
Example of molecules:
* Calcium ion
*Mineral ion
1.The Calcium ion from outside will attach at carrier protein
2.ATP energy will hydrolysis to ADP + Phosphate group
3.The phosphate group will attach to carrier protein
4.The carrier protein will uses the energy from phosphate group to change it shape
5.The Calcium ion dettach and enter into the cell with using energy
Animal Cell
Hypotonic
Meaning-The solution which have higher concentration of water molecules (H2O)
-The water molecules will enter into the cytoplasm of red blood cell
-Red blood cell will keep on expand
-Since red blood cell does'nt have cell wall,the water molecules seep into red blood cell causes it expands
-And then,red blood cell will undergo hemolysis and burst
Isotonic
Meaning-The solution which have same concentration with cytoplasm solution
-There is no movement and the animal cell will keep remain
Hypertonic
Meaning-The solution which have lower concentration of water molecules (H2O)
-The water molecules from cytoplasm red blood cell seep out to the hypertonic solution
-It will become smaller
-Crenation of red blood cells will occur
Plant cell
Isotonic
-There is no net of water molecules movement
-The plant cell wall will remains it shape
Hypotonic
-The water molecules enter from the hypotonic solution into cytoplasm of the cell
-It will causes the vacuole to be expand
-And then,cytoplasm will push until the cell wall
-The plant cell will turgid
-The water molecules will seep out from cytoplasm of the cell to the hypertonic cell
-It will causes the vacuole to be smaller
-The plant cell will become flaccid
-The plant cell undergo plasmolysis process
-If want the plant cell back to normal shape,we must put it in hypotonic solution
-The process is known as deplamolysis
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