Campbell biology chapter 7
Terms in this set (58)
a hydrophilic and hydrophobic region; phosholipid is this
Fluid mosaic model
How phospholipids and proteins are arranged in the membrane of cells; membrane is a fluid structure with a mosaic of various proteins embedded or attached to a bilayer of phospholipids
Proteins that Penetrate the hydrophobic core of the lipid bilayer, completely embedded in the membrane, some of which are transmembrane proteins that span the membrane completely
Span the whole membrane
Proteins that are not embedded in the lipid bilayer at all; loosely bound to the surface of the membrane
Membrane carbohydrates that are covalently bonded to lipids
Membrane carbohydrates that are covalently bonded to proteins
Theory that describes a phospholipid bilayer between two layers of proteins
Cause of familial hypercholesterolemia
Defective LDL receptors on the cell membranes
Selective Permeability depends on
Type of transport proteins that are present in membrane and bilayer, being permeable to primarly small, nonpolar molecules
Cell to cell regocnition depends on
Function of cholesterol in animal cell membranes
Maintains membrane fluidity
Normal tonicity condition for animal cells
Normal tonicity condition for plant cells
Great proportion of unsaturated phospholipids
What factor would tend to increase membrane fluidity?
Production of cell walls by plant cells
Process of exocytosis is important in
What mechanisms do plants use to load sucrose produced by photosynthesis into specialized cells in the veins of leaves?
Carrier molecules in the membrane and metabolic energy are required for
Surface of an integral membrane would be best described as
Integral membrane proteins are usually:
Unsaturated phospholipids and cholesterol molecules help membranes remain:
Contributes to membrane potential
The sodium potassium pump is called an electrogenic pump because it
Lateral mobility of lipids and proteins
Lack of covalent bonds between the lipids and proteins and weak hydrophobic interactions among the components in the interior of the membrane account for:
An organism with a cell wall would have the most difficulty doing what?
Cholesterol enters cells via
In a hypotonic solution an animal cell will
Small and hydrophobic
What kind of molecules pass through a cell membrane most easily?
Ions diffuse across membranes down their
Cotransport is used for
Pumping H+ ions to get sucrose into the cell
Type of bulk transport, bringing materials into the cell
Through a protein
How do ionic substances cross a membrane?
Diffusion of a substance through a protein pore
Decrease extracellular pH
What experimental treatment would increase the rate of sucrose transport into the cell?
What happens if you put an animal cell in a hypertonic solution?
What does the fluid part of the fluid-mosaic model mean?
High to low concentration, passive transport
crucial in cell-cell recognition and developing organisms
Proteins that facilitate the movement of water in a membrane, accelerate the speed at which water crosses membranes
2 things being transported at the same time
Taking stuff out of the cell; type of bulk transport
What happens if you put a plant cell into an isotonic solution?
Diffusion of water
Molecules that are hydrophobic and dissolve through the membrane easily
Help hydrophilic substances avoid the lipid bilayer; ; provide a hydrophilic channel through which molecules in question can pass; bind loosely to the molecules and carry through the membrane
No net movement of water across the plasma membrane, water crosses at the same rate in both directions
Cell will lose water to its surroundings in this solution, more solutes in the water around the cell, hence, the movement of water to the higher concentration of solutes, cell loses water to its environment
Water will enter the cell faster than it leaves in this solution, fewer solutes in the water around the cell, the movement of water into the cell where solutes are more heavily concentrated, cell will swell and may burst
Ions and polar molecules
Molecules that cannot pass easily across the membrane
Process by which ions and hydrophilic substances diffuse across the cell membrane with the help of transport proteins
Transmembrane protein that pumps sodium out of the cell and potassium into the cell; necessary for proper nerve transmission and is a major energy consumer in your body
Cell is negatively charged compared to the outside; the difference in electric charge across a membrane is expressed in voltage and is called:
Ion's concentration gradient
Attracts positively charged ions and repels negatively charged ions
combination of chemical force and voltage gradient
A transport protein that generates voltage across the membrane
ATP pump that transports a specific solute indirectly drives the active transport of other substances, substance that was initially pumped across the membrane (H+) can do work as it moves back across the membrane by diffusion and brings it with a second compound (sucrose) against its gradient
Certain substances bind to specific receptors, and this causes a vesicle to form around the substance and then pinch of into the cytoplasm
Breaking down of specific euryhrocytes; cytolysis for red blood cells