Study notes on osmosis, homeostasis, the cell membrane and types of transport
- Active transport process
- Vesicles: small spheres a membrane
- Function in movement of material
- Occurs when larger molecules or big clumps of material need to be transported
- Endocytosis & Exocytosis
Vesicular Transport- image
ENDOCYTOSIS VS EXOCYTOSIS
Used for large molecules, clumps of food and even whole cells
Used to get rid of wastes or release valuable materials cells have made
ex) releasing hormones like dopamine
Receptor - Mediated Endocytosis
simple vs facilitated diffusion
assisted by carrier protiens
occurs through the phospholipid bilayer
occurs through the membrane protiens
small and non polar molecules transported
large and polar molecules transported
rate of diffusion is directly proportional to the concentration gradient and he membrane permeability of the solute molecule
rate depends the carrier protein o
In terms of molecules, explain what happens to a sugar cube when it is placed into a beaker of water.
The sugar cube dissolves in the water, the sugar molecules break apart and dissolve in the water which is a solvent and the sugar cube is the solute.
A substance that is dissolved in a solution.
In a solution, the substance in which the solute dissolves.
A mixture that forms when one substance (the solvent) dissolves another (the solute).
A property of a plasma membrane that allows some substances to cross more easily than others.
The ability of a solution to cause a cell to gain or lose water; it depends partly on the concentration of non-penetrating solutes relative to the inside of a cell.
What is the relationship between rate of diffusion and molecular weight?
Lower molecular weight substances diffuse faster; Higher molecular weight substances diffuse slower.
What does heating water do to the rate of diffusion of tea?
Higher temperatures increase the rate of diffusion.
What enviornment do plant cells work best at and why
hypotonic Water is constantly pushed up against the cell. The cell swells, but the cell wall prevents it from bursting.
consumption of too much water, over dilutes necessary ions and can cause death, osmoregulation failure
Passive vs Active transport
requires energy in the form of ATP
does not require energy
occurs AGAINST the concentration gradient
occurs DOWN the concentration gradient
from low to high concentration
from high to low concentration
Tonicity and Osmosis
What is tonicity?
Measure of water pressure inside a cell compared to outside the cell.
Tonicity and Osmosis
The concentration of the solute outside the cell are LOWER than inside the cell
The concentration of the solute outside the cell are EQUAL than inside the cell
The concentration of the solute outside the cell are HIGHER than inside the cell
The water moves to the higher solute concentration inside the cell
The water has no net movement and nothing happens to the cells.
The water leaves the cell to the higher solute concentration
cell swells and can burst
plant cells work best
human cells work best
low osmotic pressure
equal osmotic pressure
high osmotic pressure
Transport and Cell Membrane
What is cell transport?
Cell transport is the movement of substances across the cell membrane
What is the most important feature of the cell’s phospholipid membrane?
The phospholipid bilayer because it's selectively permeable.
Why is it important that cell membranes help maintain the homeostasis within the cell
So certain things that shouldn't be in our cells can get in and the things we do need can.
What is the function of transport proteins embedded in the cell membrane?
They move larger molecules in and out of the cell because they cant pass through the phospholipid bilayer
Real life scenarios
What type of transport is a friend spraying perfume in a room and you not noticing it for a few minutes
Diffusion is used when someone prays perfume, the molecules with the scent in them will spread out across the room more and more.
If the amoeba was placed in salt water the amoeba will shrink because the solute concentration in the salywater is greater than in the amoeba so the water in the amoeba moves out to the salt water making the amoeba shrink.
I think they would use phagocytosis because phagocytosis is taking in a large molecule that will eventually digest inside the cell. Or they use endocytosis because endocytosis is take in molecules.
Explain the difference between osmosis and diffusion
in diffusion all particles move freely down concentration gradients. In osmosis only water (solvent) molecules move across a partially permeable membrane from a dilute solution to a concentrated solution.