Chapter 7 Flashcards
Amphipathic
One side is hydrophilic while the other is hydrophobic
Hydrophobic interaction
Weak chemical interaction caused when hydrophobic molecules form together to exclude water
Which fatty acids make phospholipids more fluid
Unsaturated carbontails
Which fatty acids make membrane more viscous
Saturated fats
Function of cholesterol in the membrane
Acts as a fluid buffer, and lowers temperature required to solidify membranes
Integral proteins
Transmembrane protein with hydrophobic and hydrophilic regions
Transmembrane proteins
Type of integral protein that goes through membrane
Peripheral protein
Protein loosely bound to the surface of a membrane or part of an integral protein
What holds membrane proteins in animal cells
Cytoskeletons on the cytoplasm side
Functions of plasma membrane proteins
Transport, enzymatic activity, cell-cell recognition, attachment to cytoskeleton & ECM
Glycolipids
Lipids with one or more covalently attached carb
Which substances struggle getting past the membrane
Polar molecules and ions
Transport protein
Transmembrane protein that helps substances cross membranes
Diffusion
Random thermal motion of molecules
What does diffusion do
A net movement of a substance from higher concentration to lower concentration
What happens if diffusion goes on for long enough
Dynamic equilibrium
Concentration gradient
Region which the density of a substance increases or decreased
Passive transport
Diffusion of a substance across membrane without using energy
Osmosis
Diffusion of free water across a selective barrier
Isotonic
A solution that causes no net movement of water into or out of cells
Tonicity
The ability of a solution surrounding a cell to cause it to lose or gain water
Hypertonic
Solution that causes the cell to lose water
Hypotonic
Solution that causes a cell to take up water
Osmoregulation
Regulation of solute concentration and water balance by a cell or organism
Plasmolyze
Cytoplasm shrivels and membrane pulls away from cell wall
(Occurs in walled cells)
Facilitated diffusion
Passage of substance down electrochemical gradient with help of transmembrane transport protein
Active transport
Movement of substances across a cell membrane against its concentration/electrochemical gradient
Membrane potential
Difference in electrical charge across a membrane due to unequal distribution of ions
Electrochemical gradient
Diffusion gradient of ions which is affected by chemical and electromagnetic forces
Electrogenic pump
Active transport protein that generates voltage across a membrane while pumping ions
Cotransport
Coupling of the downwards diffusion of a substance with upwards transport of another substance against its concentration gradient
How do macromolecules get into or out of cells
Vesicles
Exocytosis
secretion of biological molecules by fusing vesicles with the membrane
Endocytosis
Cellular uptake of molecules by forming vesicles from plasma membrane
Receptor mediated endocytosis
Movement of molecules into a cell by specific molecules into the cell in bulk
