Movement in and out of cells Flashcards
Define DIFFUSION
The net movement of molecules or ions from a region of high concentration to a region of low concentration down a concentration gradient
What are the factors that affect diffusion?
Size of molecule, Distance, Surface area, Temperature and the steepness of the concentration gradient
Cell membranes are partially permeable. What does this mean?
It means that it only allows small molecules to pass through
Define OSMOSIS
The diffusion of water molecules from a region of their higher concentration(dilute solution) to a region of their lower concentration(concentrated solution) through a partially permeable membrane
Where does water molecules diffuse down?
A water potential gradient from a region of higher water potential to a region of lower water potential
Define TURGID
Full of water
Define FLACCID
Just the right amount of water
Define PLASMOLYSED
NOT enough water
Define ACTIVE TRANSPORT
The movement of ions or molecules across the cell membrane, against a concentration gradient, using energy from respiration
What does ACTIVE TRANSPORT enable the root hair cell to take up?
Ions and epithelial cells of the villi to take up glucose
Which is NOT partially permeable?
A. Cell membrane of palisade mesophyll cell
B. Cell membrane of red blood cell
C. Cell wall
D. Dialysis tubing
C
Root hair cells are surrounded by soil water, which is very dilute solution of mineral ions such as nitrate ions and magnesium ions. Plant cells have higher concentrations of these ions. How do root hair cells absorb ions from soil water?
A. Active transportation
B. Diffusion
C. Osmosis
D. Random movement
A
What does ACTIVE TRANSPORT enable the root hair cell to take up?
Ions and epithelial cells of the villi to take up glucose
