module 7: plasma membrane

What would you expect to happen to a cell with a high proportion of phosphatidylserine on the exoplasmic face of the membrane?

it undergoes apoptosis

Small transient structures rich in sphingomyelin and cholesterol that concentrate particular proteins in the membrane are called what?

lipid rafts

primary active transporter (pump) functiondirectly hydrolyzes ATP to move two molecules against their concentration gradients

primary active transporter (pump)

gradient-driven pumps that move one molecule down its concentration gradient in order to move a second molecule against its gradient

secondary active transporter (pump) 

selectively bind molecules (i.e., glucose) then change shape to transport them across the membrane

carrier protein

form pores in the membrane that allow the passage of small hydrophilic molecules, like ions and water. to cross

channel protein

How many molecules of Na⁺ and K⁺ are moved across the membrane by the Na⁺/K⁺ pump and in which direction?

3 na out and 2 k in

What is the major functional difference between primary active and secondary active transporters?

Primary directly hydrolyze ATP and secondary uses sodium gradient

extracellular molecule binds to a cell's membrane-bound receptor, triggering endocytosis of the receptor:molecule complex

clathrin endocytosis

most cells can perform this action of endocytosing a large portion of nutrient-rich extracellular fluid

macropinocytosis

white blood cells engulf a large particle, such as a bacterium

phagocytosis

Which type of endocytosis is an example of a clathrin-independent mechanism? 

macropinocytosis

Membrane proteins, like receptors, engulfed during endocytosis are most often what?

recycled

what are two structural features that are critical to the phospholipid bilayer?

amphipathic, viscous fluids

? are gentle detergents that do not denature proteins, Triton X

? disrupts hydrophobic protein regions that denature proteins, SDS

nonionic, ionic

which proteins are embedded in the phospholipid bilayer?

integral

which proteins are associated with the membrane indirectly and are attached to the integral proteins on one side of the bilayer?

peripheral

what is a carbohydrate coat that regulates movement of fluids between cells?

glycocalyx

Tight junctions between epithelial cells lead to ? and ? domains

apical, basolateral

what are subsets of lipid rafts formed by oligomers of integral membrane protein caveolin?

caveolae

Which type of endocytosis is an example of a clathrin-dependent mechanism? 

phagocytosis

phagocytosis takes in large ? like bacteria, while macropinocytosis takes in large ?.

solids, liquids

what binds to a specific solute, changes shape to move across mem, slower, and can be passive or active transport?

carrier proteins

what forms a continuous pore passage, fast, and focuses on passive transport only?

ion channels