Chapter 3 Flashcards
fluid-mosaic model
The phospholipid bilayer has a fluid consistency, similar to oil, allowing lipid molecules the freedom to move; proteins embedded on the outside or within the bilayer form a mosaic pattern
glycolipids
Phospholipids that have attached carbohydrate (sugar) chains. Located on the outside of cell membranes
glycoproteins
Proteins that have attached carbohydrate (sugar) chains
phospholipids
Phospholipids are constructed similar to neutral fats (triglycerides), except a phosphate group takes the place of one of the fatty acids; the main constituent of the plasma membrane; hydrophilic (water-loving) heads of the molecule face the outsides and insides of the cell; hydrophobic (water-fearing) tails face each other in the inner part of the membrane
selectively permeable or semipermeable
Describes to the cell membrane because some molecules can through it while others cannot
selectively permeable or semipermeable
Describes to the cell membrane because some molecules can through it while others cannot
concentration gradient
Small, non-charged molecules, such as carbon dioxide and oxygen, diffuse through a plasma membrane from an area of high concentration to an area of low concentration
diffusion
The movement of molecules from an area where the molecule is in high concentration (more solute) to an area of lower concentration (less solute)
facilitated diffusion (transport)
the movement of a molecule, with the aid of a protein channel or carrier, from an area of high concentration to an area of lower concentration
hypertonic solution
Hyper means ‘more than’ and refers to a solution with more solute (and therefore less water) than found inside a cell; an animal cell placed in a hypertonic solution will shrink or shrivel up due to the movement of water out of the cell
hypotonic solution
Hypo means ‘less than’ and refers to a solution with less solute and more water than found inside a cell; a cell placed in this solution will take on water and swell or even burst
isotonic solution
The same concentration of solute and water, both inside and outside the cell
lysis
Bursting of a cell due to the build-up of pressure
osmosis
Diffusion of water through a semi-permeable membrane due to concentration differences; water moves from an area of high water molecule and low solute concentration to an area of low water molecule and high solute concentration
osmotic pressure
The force that causes water to move in either direction across a semi-permeable membrane
passive transport
Involves diffusion or facilitated transport; no chemical energy is required
plasmolysis
Occurs in plants cells placed in a hypertonic solution; cytoplasm is reduced due to osmosis and the plasma membrane pulls away from the cell wall
turgor pressure
Occurs in plant cell placed in a hypotonic solution; swelling creates turgor pressure, but the plant cell will not burst because the plasma membrane pushes against the rigid cell wall
active transport
By this process, ions and molecules move across the cell’s plasma membrane and accumulate inside or outside the cell; the carrier requires energy to change its shape and transport the molecule to the other side of the membrane
endocytosis
Requires the use of a cell’s ATP energy to alter the shape of the membrane surface (called invagination) to allow a macromolecule to be completely surrounded by the membrane, which then pinches together to form an intracellular vesicle inside the cytoplasm of the cell
endocytosis
Requires the use of a cell’s ATP energy to alter the shape of the membrane surface (called invagination) to allow a macromolecule to be completely surrounded by the membrane, which then pinches together to form an intracellular vesicle inside the cytoplasm of the cell
exocytosis
The movement of materials out of the cytoplasm; ATP energy is needed to create a vesicle or vacuole (large vesicle) that will migrate to the membrane’s inner surface and fuse with the cell membrane
phagocytosis
Endocytosis of large particles
pinocytosis
Endocytosis of liquid and very small particles