Membranes

Glycolipids

________: lipids that are covalently bonded to monosaccharides or polysaccharides.

Amount of cholesterol

________ found is membrane- type and organism dependent.

Sphingomyelin

________: only cell membrane not derived from glycerol.

Channels

________: form an open passageway for the direct diffusion of ions or molecules across the membrane.

protein composition

Percentage of lipid and ________ depends on membrane location.

Membranes

________ also contain proteins and carbohydrates.

Lipids

________- provide the foundation /support.

Antigenicity

________: has to do with recognizing cells or non- cells.

Cells

________ can create diffusion barriers which restrict proteins to one area /domain.

conformational change

Transporters: also known as carriers; ________ transports solute across membrane.

Microdomains

________: cholesterol and sphingomyelin enriched area of a membrane.

Phosphatidylcholine

________ (no net charge): most common lipid in cell membranes.

Anchors

________: integrins link intracellular actin filaments to extracellular matrix proteins.

Antiporter

________: two or more ions or molecules transported in opposite directions.

extracellular structures

Some proteins are linked to ________ or tethered to the cell cortex.

Symporter

________ or cotransporter: two or more ions or molecules transported in same direction.

Flexibility

________: membranes are able to bend.

Peripheral

________ or extrinsic membrane proteins: noncovalently bound either to integral membrane proteins that project out from the membrane, or to polar head groups of phospholipids.

cholesterol

Ie: The higher the ________ concentration the greater the reduction in proton and sodium permeability.

Enzymes

________: adenylyl cyclase catalyzes the production of intracellular cyclic AMP in response to extracellular signals.

chemical damage

Protects cell surface from mechanical and ________.

Fluid Mosaic

________ in which lipids and proteins are mobile- 2D fluid.

mechanical properties

Determines the shape of the cell and the ________ of the plasma membrane.

Transport proteins

________: transmembrane proteins that provide a passageway for the movement of ions and hydrophilic molecules across membranes.

Proteoglycans

________ have one or more long polysaccharide attached.

Presence of double bonds

________: a double bond creates a kink in the fatty acyl tail, making it more difficult for neighboring tails to.

Membrane glycoproteins

________ contain short oligosaccharides extending to the extracellular space.

Phospholipids

________ are amphipathic molecules.

Receptors

________: PDGF receptor signals cause the cell to grow and divide.

Transmembrane proteins

________: region (s) are physically embedded in the hydrophobic portion of the phospholipid bilayer.

Intracellular attachment proteins

________ attach spectrin to specific transmembrane proteins which serves to connect spectrin meshwork to the membrane.

Plasma membrane proteins

________ are usually localized to specific areas within the bilayer= membrane domains.

Presence of cholesterol

________: cholesterol tends to stabilize membranes.

Membrane glycolipids

________ do not protrude into the cytoplasm.

Lipid

________- anchored: an amino acid of the protein is covalently attached to a(n) ________.

Membranes

________ are called a lipid bilayer.

Lipids

provide the foundation/support

Fluid Mosaic in which lipids and proteins are mobile

2D fluid

Flexibility

membranes are able to bend

Antigenicity

has to do with recognizing cells or non-cells

Transmembrane proteins

region(s) are physically embedded in the hydrophobic portion of the phospholipid bilayer

Lipid-anchored

an amino acid of the protein is covalently attached to a lipid

Peripheral or extrinsic membrane proteins

noncovalently bound either to integral membrane proteins that project out from the membrane, or to polar head groups of phospholipids

Length of fatty acyl tails

shorter acyl tails are less likely to interact, which makes the membrane more fluid

Presence of double bonds

a double bond creates a kink in the fatty acyl tail, making it more difficult for neighboring tails to

Presence of cholesterol

cholesterol tends to stabilize membranes

Phosphatidylcholine (no net charge)

most common lipid in cell membranes

Sphingomyelin

only cell membrane not derived from glycerol

Glycolipids

lipids that are covalently bonded to monosaccharides or polysaccharides

Cholesterol

Lipid soluble steroid

Ie

  The higher the cholesterol concentration the greater the reduction in proton and sodium permeability

Microdomains

cholesterol and sphingomyelin enriched area of a membrane

Transporters

Na+ pump actively pumps Na+ out of cells and K+ in

Anchors

integrins link intracellular actin filaments to extracellular matrix proteins

Receptors

PDGF receptor signals cause the cell to grow and divide

Enzymes

adenylyl cyclase catalyzes the production of intracellular cyclic AMP in response to extracellular signals

Transport proteins

transmembrane proteins that provide a passageway for the movement of ions and hydrophilic molecules across membranes

Channels

form an open passageway for the direct diffusion of ions or molecules across the membrane

Example

Aquaporins

Transporters

also known as carriers; conformational change transports solute across membrane

Uniporter

single molecule or ion

Symporter or cotransporter

two or more ions or molecules transported in same direction

Antiporter

two or more ions or molecules transported in opposite directions