Movement across the cell membrane
aquaporin
"water-hole". The channel through which water diffuses through in a cell membrane
hypertonic
(of a solution) having a higher osmotic pressure than a comparison solution. Cells shrink in hypertonic solutions.
hypotonic
(of a solution) having a lower osmotic pressure than a comparison solution. Cells swell in a hypotonic solution.
channel protein
A membrane protein, specifically a transport protein, that has a hydrophilic channel that certain molecules or atomic ions use as a tunnel.
endocytosis
A process in which a cell engulfs extracellular material through an inward folding of its plasma membrane.
carrier protein
A protein found in membranes, which is capable of carrying a specific molecule or ion through the membrane by active transport.
channel proteins
A protein pore that spans a membrane, through which very small ions and water soluble molecules may pass.
plasma membrane
A selectively-permeable phospholipid bilayer forming the boundary of the cells
phagocytosis
A type of endocytosis in which a cell engulfs large particles or whole cells. Also known as "cell eating"
pinocytosis
A type of endocytosis in which the cell ingests extracellular fluid and its dissolved solutes. also known as "cell drinking"
Cells in a hypotonic solution
An animal cell swells until pressure bursts it, resulting in cell death. This does not happen to plant cells because they have a cell wall. (the plant cell will expand but will not burst). What kind of solution are the both cells placed in?
turgor
Condition of being distended or swollen; normal fullness
Fluid Mosaic Model
Describes the following properties of the cell membrane: 1. cell membrane is fluid, flexible and moves. 2. cell membrane is composed of proteins, lipids and carbohydrates.
osmosis
Diffusion of water through a selectively permeable membrane
exocytosis
Process by which a cell releases large amounts of material A process in which a cell releases substances to the extracellular environment by fusing a vesicular membrane with the plasma membrane, separating the membrane at the point of fusion and allowing the substance to be released.
ion pump
Proteins move ions across a membrane (hydrogen, sodium or potassium); requires ATP
Plasma membrane (cell membrane)
Regulates what enters and leaves the cell and separates the internal environment of the cell from the external environment
passive transport
Requires NO energy, Movement of molecules from high to low concentration, Moves with the concentration gradient
Osmosis
The diffusion WATER across a selectively permeable membrane.
CONCENTRATION GRADIENT
The gradient in molecular concentration (the difference in concentrations) that allows diffusion to occur
facilitated diffusion
The movement of molecules across a semi permeable membrane from an area of high concentration to an area of low concentration and which is aided by carrier protein molecules or protein channels. No metabolic energy ois required.
Diffusion
The movement of molecules from an area of high concentration to area of low concentration.
osmosis
The movement of water molecules from a region of higher water potential to a region of lower water potential across a partially permeable membrane.
diffusion
The net movement of molecules from an area of high concentration to an area of low cencentration.
Plant cells in a hypertonic solution
The plant cell shrinks inside its cell wall while the cell wall remains intact. What kind of solution is the plant cell placed in?
exocytosis
The process of removing materials from the cell by fusing vesicles containing the material with the plasma membrane (cell surface membrane).
endocytosis
The process of taking materials into a cell by surrounding them with part of the plasma membrane, which then pinches off to form a vesicle inside the cell. This is an active process requiring ATP
selectively permeable
a property of cell membranes that allows some substances to pass through, while others cannot
Sodium- Potassium pump
a protein that uses ATP to actively transport sodium ions out of a cell and potassium ions into the cell
cell wall
a structure that surrounds a cell to provide structural support.
concentration gradient
A difference in the concentration of a substance across a distance. When something diffuses, it travels with the concentration gradient.
Concentration gradient
A difference in the concentration of solutes on one side of the cell membrane compared to the other side.
isotonic
Having the same solute concentration as another solution.
transmembrane protein
Integral proteins that span the membrane.
Phospholipid
Makes up the cell membrane; has 1 head (hydrophilic) and 2 tails (hydrophobic)
Hydrophilic
Means "water lovings" Describes the heads (circle portion) of the phospholipids
Hydrophobic
Means water fearing. Describes the tails of the phospholipids
glycolipids
Membrane carbohydrates that are covalently bonded to lipids.
glycoproteins
Membrane carbohydrates that are covalently bonded to proteins.
diffusion
Movement of molecules from an area of higher concentration to an area of lower concentration.
facilitated diffusion
Movement of specific molecules across cell membranes through protein channels
active transport
Movement of substances across a semi permeable membrane from an area of low concentration to an area of high concentration. Requires the use of energy in the form of ATP and either carrier protein or protein channels.
Active transport
Movement of substances across the cell membrane that require extra energy.
Non-Polar Tail
Part of the phospholipid that is not attracted to water.
fluid mosaic model
Structural model of the plasma membrane where molecules are free to move sideways within a lipid bilayer.
Bilayer
The cell membrane is made of two layers of lipid molecules.
Selectively permeable
The term to describe a cell membrane that allows some substances to pass, but not others
Facilitated diffusion
The type of cell transport in which large molecules (like glucose) move across the membrane with help from proteins.
Hypertonic solution
The type of solution that causes water molecules to leave the cell, and cell shrivels up and dies.
Hypotonic solution
The type of solution that causes water molecules to move into the cell and the cell swells
Isotonic solution
The type of solution when the same amount of water molecules enter and leave the cell.
Carbohydrates
This component of the cell membrane allows different cells in your body to identify each other.
Channel protein
This component of the cell membrane allows the transport of specific substances across a cell membrane.
Protein
This component of the cell membrane are channels that transports substances.
plasmolysis
This happens when a cell shrinks inside its cell wall while the cell wall remains intact.
Passive transport
When substances move across the membrane without using extra energy (naturally happens).
active transport
moving stuff across the cell membrane with ATP (energy), typically against the concentration gradient
Polar Head
part of the phospholipid that is attracted to water.
carrier proteins
proteins change shape as it carries out facilitated diffusion