Subject: Do red blood cells breath or metabolize? Are they even 'alive'?

Red blood cell contain no nucleus and no DNA, hence it cannot, 
and does not, reproduce itself. Since it has no DNA it cannot 
produce RNA and subsequent proteins necessary for various 
function. Do red blood cells absorb any nutrient in the blood 
stream? and do they breath and use up the oxygen it carry? As 
far as i know their only function is to bind to oxygen, 
preventing oxygen from turning into gas form, and then float 
around in the blood stream, unable to direct its own course. If 
they don't metabolize nor breath nor reproduce, how could they 
be consider a living thing? So are red blood cells a "living" 
cell? or are they just a complex compound of molecules and 
chemical? 

Re: Do red blood cells breath or metabolize? Are they even 'alive'?