18 terms

Chapter 4

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[glucose]
This symbol [ ] means concentration, specifically the concentration of glucose. You can put anything in the [ ] that you want to express in terms of concentration.
Passive Transport
The movement of a substance from [high] to [low] without the use of energy. Can be directly through the cell membrane or through special proteins.
Concentration Gradient
The difference in [ ] of a substance across a space.
Equilibrium
[substance] is equal throughout a space
Diffusion
Movement of any substance from [high] to [low] through the cell membrane only and requires no energy.
Osmosis
Diffusion of water through a selectively permeable membrane (like the cell membrane)
Hypertonic Solution
Water moves out of the cell and causes a cell to shrink because of osmosis.
Hypotonic Solution
Water moves into the cell and causes a cell to expand because of osmosis.
Isotonic Solution
Water moves at equal rates causing no change in the size of a cell.
Ion Channel
A transport protein that ions (charged atoms) move through.
Carrier Protein
A transport protein that transports a specific substance.
Facilitated Diffusion
A type of passive transport that uses a carrier protein.
Active Transport
A type of active transport that moves a substance from [low] to [high] (against the gradient)
Sodium-Potassium Pump
A carrier protein used in active transport important for nerve cells.
Endocytosis
A type of active transport that moves a large substance INSIDE the cell with the use of a vesicle.
Exocytosis
A type of active transport that moves a large substance OUTSIDE the cell with the use of a vesicle.
Receptor Protein
A type of protein that binds to a signal molecule, enabling the cell to respond to the signal molecule.
Second Messenger
Acts as a signal molecule in the cytoplasm.