A molecule with both hydrophilic and hydrophobic regions
Aquaporin
Water channel proteins that facilitates the diffusion of massive amounts of water across a cell membrane.
Concentration gradient
An increase or decrease in the density of a solute in an area.
Cotransport
Occurs when the active transport of a specific solute indirectly drives the active transport of another solute.
Diffusion
🍊 The movement from a higher to lower concentration.
Electrochemical gradient
The diffusion gradient of an ion. (The cytoplasm is negative, so cations go inside the cell. The extracellular fluid is postive, so anions go outside the cell.)
Electrogenic pump
A transport protein that generates the voltage across the membrane.
Endocytosis
The cellular uptake of macromolecules through a membrane by folding and pinching off vesicles.
Exocytosis
The cellular secretion of macromolecules by fusion of vesicles with the plasma membrane.
Facilitated diffusion
Move from HIGH to LOW concentration with
Flaccid
Limp. (When a plant cell is in an isotonic environment / water does not move)
Fluid mosaic model
A model of the plasma membrane.
Gated channel
A protein in a cell membrane that opens up or closes in repsonse to a particular stimulus.
Glycolipid
A lipid covalently attached to a carbohydrate.
Glycoprotein
A protein covalently attached to a carbohydrate.
Hypertonic
Higher concentration of solute.
Hypotonic
Lower concentration of solute.
Integral protein
Proteins that penetrate into lipid bilayer, often completely spanning the membrane.
Ion channel
Protein channel in a cell membrane that allows passage of a specfic ion down its concentration gradient.
Isotonic
Equal concentration of solute.
Ligand
Any molecule that binds specifically to a receptor site of another molecule).
Membrane potential
The voltage difference across a membrane.
Osmoregulation
Balancing water uptake and loss.
Osmosis
Diffusion of water across a semipermeable membrane,
Passive transport
Diffusion going from a high to low concentration without the usage of energy.
Peripheral protein
Proteins loosely bound to the surface of the plasma membrane.
Phagocytosis
Form of endocytosis of solid matter.
Pinocytosis
Form of endocytosis of liquid matter.
Plasmolysis
The process where a cell shrivels up and loses water in a hypertonic environment.
Proton pump
An active transport mechanism in cell membranes that uses ATP to force hydrogen ions out of a cell, generating a membrane potential in the process.
Receptor-mediated endocytosis
Process where a cell take up large amounts of very specific molecules.
Selective permeability
A property of membranes that allow some substances to pass through, others not.
Sodium-potassium pump
Active transport where animal cells transport sodium out of the membrane and potassium into the membrane. (Pumps two K+ ions for every three Na+ ions).
Tonicity
The ability of a solution to cause a cell to lose or gain water.
Transport protein
Proteins that helps substances to move across the membrane.
Turgid
Very firm (healthy state of plant cells when they are in a hypotonic environment).