Unit 2: Flashcards
Phospholipids
Main fabric of the membrane
Cholesterol
Tucked between the hydrophobic tails of the membrane phospholipid s
Integral proteins
Embedded in the phospholipid bilayer; may or may not extend through both layers
On the inner or outer surface of the phospholipid bilayer, but not embedded in its hydrophobic core
Carbohydrates
Attached to proteins or lipids on the extra cellular side of the membrane (forming glycoproteins and glycolipids).
Cell membrane
Specialized structure that surrounds the cell and its internal environment; controls movement of substance es into/out of cell
Hydrophobic Molecule that repeals water (“water-fearing”)
Hydrophilic
Molecule that is attracted to water (“water-loving”)
Amphipathic
Molecule that contains both a hydrophobic and hydrophilic end
Phospholipid
Amphipathic lipid made of glycerol , two fatty acid tails, and phosphate group
Phospholipid bilayer
A biological membrane involving two layers of phospholipids with their tails pointing inward
Semipermeable membrane
Membrane that allows certain substances to pass through
Passive Transport
Type of transport that does not require energy to occur and be used in the process
Concentration gradient
A region of space over which the concentration of a substance changes, and substances will naturally move down their gradients, from an area of higher to area of lower concentration
Permeability
The quality of a membrane that allows substances to pass through it
Equilibrium
The state at which a substance is equally distributed throughout a space
Active transport
Type of transport that requires an input of energy to occur
Concentration gradient
A region of space over which the concentration of a substance changes
ATP
Adenosine triphosphate, the primary energy carrier in living things
Electrochemical gradient
The combination of a concentration gradient and voltage that affects and ions movement is called the electrochemical gradient
Primary active transport
directly uses a source of chemical energy (e.g., ATO) to move molecules across a membrane against their gradient
Secondary active transport (contransport)
, on the other hand, uses an electrochemical gradient - generated by active transport - as an energy source to move molecules against their gradient, and thus does not directly require a chemical source of energy such as ATP
Osmosis
The net movement of water across a semipermeable membrane from an area of lower solute concentration to an area of higher solute concentration
Osmolarity
Describes the total concentration of solutes in a solution
Tonicity
The ability of an extracellular solution to make water move into or out of a cell by osmosis is known as this
Endosymbiotic theory
Theory proposing that eukaryotic cells formed from a symbiotic relationship among prokaryotic cells.
