Movement in and out of cells Flashcards
(19 cards)
What is Diffusion?
Diffusion is the net movement of molecules from a region of high concentration to a region of lower concentration down a concentration gradient
What is the movement of molecules by diffusion across a cell membrane called?
Passive movement
What 5 factors affects diffusion and why?
The distance a molecules have to travel - Cell membranes are very thin.
Concentration gradient - The higher the difference in concentration, the higher the diffusion rate.
Surface area - Folds in cell membranes allow higher diffusion rates.
Temperature - Hotter molecules faster, so they also diffuse faster.
Size of molecules - Smaller molecules diffuse faster than big ones.
What is a solution made of?
A solution is made of two parts: Solute and solvent.
What is the solute?
The solute is the substance dissolved in a solvent.
What is the solvent?
The solvent is the substance where the solute is dissolved.
What are substances that can be dissolved in a solvent described as?
They are described as soluble.
What is a universal solvent?
Water
Read
Osmosis is a special kind of diffusion involving water molecules.
When does Osmosis occur?
Osmosis occurs when two solutions are separated by a partially permeable membrane - Like the cell membrane.
What is osmosis?
The diffusion of water from a high dilute solution into a more concentrated one.
Describe osmosis
The water flows from a high water potential to a low water potential region, down a water potential gradient.
Read
Because of the cell wall present in Plant cells, animal and plant cells respond differently to osmotic pressure.
What is is called when substances need/ are transported against the concentration gradient.
Active transport.
What does this require the use of?
Carrier proteins, and energy produced by cell respiration.
Which requires no energy? Diffusion, or active transport
Diffusion requires no energy
Which doesn’t use proteins? Diffusion or active transport?
Diffusion
Which goes against a gradient? Diffusion or active transport?
Active transport
Which is non saturable? Diffusion or active transport?
Diffusion
