cavalier

right now i'm watching game one of the nba finals. detroit has to be one of the most underrated teams in professional sports history. who's given them any respect in the past two years? detroit's only up 27-24 right now, but even if san antonio goes on to win the series, detroit, in my mind, has earned its wings as one of the great nba teams of the past 25 years.

although they're primarily known for their stingy defense, one of the pistons' hallmarks is its "flex" offense. many teams employ a flex offense, including my beloved university of maryland terrapins, particularly when they feature quick, accurate-shooting guards like juan dixon or, detroit's star guard, richard hamilton. you'll often hear the word "curl" and "rotation" associated with flex offenses. the guard moves in a circle about 15 feet from the basket, running through screens to get open for a mid-range jumpshot. drawn up with x's and o's, a flex offense is a bunch of curved arrows.

in cell physiology, the transport of molecules and ions across cell membranes is often facilitated by so-called transport proteins--integral membrane proteins that allow specific substances to pass in and out of cells. some of these transport proteins need a direct burst of energy to move an ion, for example, across the membrane. the most ubiquitous of these primary active transport proteins is the sodium-potassium pump, aka Na+,K+ ATPase. this ATPase is present in all cell membranes, and it pumps three Na+ ions out of the cell and two K+ ions into the cell. the way my simple brain remembers this is, "Na+" is 3 characters, so 3 sodium ions are pumped out, and "K+" is 2 characters, so 2 potassium ions are pumped in.

another important concept in characterizing transport and receptor proteins is the subunit building block. the Na+,K+ ATPase consists of an alpha and a beta subunit. the alpha subunit is the busy subunit, responsible for the ATPase enzymatic activity (-ase = enzyme) and the binding of both sodium and potassium. likewise, my current research involves examining the gene that codes for an alpha subunit of a nerve receptor. as you can probably deduce from its functions, the Na+,K+ ATPase alpha subunit isn't static--it moves in order to shuttle ions across the plasma membrane, changing shape depending on what's bound to it. specifically, when Na+ binds to the ATPase from the inside of the cell, the enzyme then undergoes a conformational change and rotates to the extracellular (outside) surface of the membrane, where it then releases the sodium and binds a potassium in exchange.

hence the flex offense and the curl. at least for me, thinking of transport proteins as dynamic, shape-shifting entities helps me understand both their functions and their roles better, rather than simply thinking "ok, Na+,K+ ATPase is 3 sodium out, 2 potassium in." like rip hamilton, the ATPase starts from one end of the membrane "court," rotates across to the other end, and releases the shot. it's not the best metaphor--whereas the ATPase alpha subunit carries the Na+ ion, hamilton moves without the ball. but whatever.

oh, and i almost forgot: cavalier! back in high school, my lacrosse team ran a cool play called cavalier, named after the university of virginia mascot. when coach called cavalier, the midfielder with the ball (me) stood up top--think the top of the key in basketball--while the three attackmen ran in a circle in front of the goal, waiting for a pass for a quick score (kinda like a flex offense). unfortunately, the play never worked in a game, but at least it always looked cool.