Cell Transport Flashcards
Passive Transport
concentration gradient
High»_space; Low
without the use of energy
Diffusion
the net movement of molecules from an area of higher concentration to an area of lower concentration
*the steeper the gradient the faster the rate of diffusion
Osmosis
the movement of water from a high concentration to a low concentration
*make sure you know the reason why water moves from high to low
Facilitated Diffusion
the movement of substances across the plasma membrane with the use of a special proteon because the substances cannot pass through without assistance.
Facilitated Diffusion
(Channel Proteins)
(ex: ions such as Na+, Cl-; Aquaporins- channel proteins for water)
molecules are moved across the membrane through a channel, specifically ions and to move water through faster.
affected by steepness of gradient and whether gated channels are open
Facilitated Diffusion
(Carrier Proteins)
(ex: glucose, amino acids)
molecules are moved across the membrane through a carrier, specifically for larger molecules like polysaccharides.
affected by steepness of gradient and whether the carrier is available
Active Transport
concentration gradient
Low»_space; High with the use of energy (ATP)
needs energy because it is going against the concentration gradient.
Active Transport
(Sodium Potassium Pump)
- 3 sodium ions bind to the pump.
- A phosphate from ATP is donated to the pump (energy used)
- Pump changes shape and releases sodium ions outside of the cell.
- 2 potassium ions bind to the pump and are transferred into the cell.
- Phosphate group is released and pump returns to its original shape
its important becuase it helps to maintain ionic concentrations inside and outside the cell that facilitate the ability of neurons to fire action potentials, which is the basis for electrical signaling within neurons.
Active Transport
(Endocytosis)
bulk transpot
a process by which cells absorb external material by engulfing it with the cell membrane by forming vesicles
pinocytosis - transfer of solutes or fluids
phagocytosis - transfer of larger particles or whole cells
receptor-mediated - uses special receptor proteins to help carry large particles across the cell membrane.
Active Transport
(Exocytosis)
bulk transport
plasma membrane moves materials outside of the cell.
Hypertonic, Hyptonic, and Isotonic
hypertonic - a solution with a higher solution concentration in comparison to another one.
hypotonic - a solution with a lower solute concentration in comparison to another one.
isontonic - solutions with equal solute concentrations.
Hypotonic Solution with Plants and Animal Cells
animal cell - lysed; the cell will burts
plant cell - turgid; the cell is perfect and full
Isotonic Solution with Plants or Animal Cells
animal cell - normal; not too full or too empty
plant cell - flaccid; normal not too full or too empty
