Transport across cell membranes Flashcards
What are cells enclosed by?
Cell membrane
Lipids have how many layers?
Two layers
What do lipids do for the cell membrane?
Make the cell membrane more flexible
What are found in Lipids?
Membrane proteins
What two words are used to describe the cell membrane?
Selectively permeable
What does Selectively Permeable mean?
Allows small molecules to pass through the cell membrane rapidly like water and oxygen and some molecules slowly like glucose but some molecule like protein are too big to pass through the cell membrane
Explain diffusion
Diffusion is the movement of molecules from a region of high concentration to a region of low concentration until the concentrations are equal
Does diffusion require energy? Justify your answer
Diffusion does not require energy
Because the molecules are going from a high concentration to a low concentration this does not require effort so does not use energy
What do the difference between the concentration of a substance called?
Concentration gradient
When does diffusion stop?
When the concentrations are equal
Does Osmosis require energy?
No it does not
What is the difference between Diffusion and Osmosis?
Diffusion is the movement of molecules
Osmosis is the movement of water molecules
