Movement of cells and SA Flashcards
What does cell membrane do?
Create barrier between cell & external enviro
What does a cell membrane consist of?
Mainly lipids & proteins. Proteins are placed complexly between phospholipids & control transport of substances in & out of cell.
What is the phospholipid bi layer?
What makes up membrane, that contains embedded proteins & carbohydrates
Phospholipid bilayer
What does cell membrane do?
Allows substances to travel in & out of cells (eg, Oxygen, glucose, CO2, excess water) and makes a barrier.
What do transport proteins do?
Some substances (eg protein) to large for cell membrane & must be moved through transport layer.
Where can smaller molecules pass through cell membrane?
Phospholipid bilayer.
What is diffusion?
Movement of molevules from area of high to low concentration.
What type of transport does diffusion use?
passive
Why does diffusion occur and where does it occur more quickly?
Because particles move. Occurrs faster in gases than liquids.(Not in solids)
In cells, what can diffusion move?
Oxygen, CO2, chloride ions
What affects rate of diffusion?
- Heat
- State of matter
- Concentration
Define osmosis
Diffusion of substance (usually H2 O) across selectively permeable membrane.
Or
Movement of H2 O from a solution of low solute conc. to high solute conc.
Active transport
movement of substnaces against concentration gradient (from H to L)
Does active transport use passive transport?
NO, needs cellular energy and uses transport proteins.
