Subject: Re: Photorespiration: energy cost
From: [email-masked] (Mark J. Hovenden)
Date: Mon, 09 May 1994 14:07:16 +1000
Newsgroups: bionet.photosynthesis

In article <[email-masked]>, [email-masked]
("Nigel Gomm") wrote:

> Does anyone know the energy cost in ATP & NADP of returning the CO2 to 
> the carbon-fixing cycle (in peroxisomes after the Calvin cycle "misfires" 
> by picking up an O2 instead of CO2 and produces the 2-carbon 
> phosphoglycolate)?
> I.E. What exactly is the inefficiency of photorespiration?

I suggest that you read the following paper which is one of the best
discussions of the cost and benefit of photorespiration, particularly in
conditions of limiting Pi.  It is an excellent paper with profound
implications for supposed greenhouse shifts in CO2 pressures.

Harley, P.C. and Sharkey, T.D. 1991. An improved model of C3 photosynthesis
at high CO2: reversed O2 sensitivity explained by glycerate reentry into
the chloroplast.  Photosynthesis Research 27, 169-178.

-- 
Mark J. Hovenden                           ph:  +61 02 202371
Dept Plant Science                         FAX: +61 02 202698
University of Tasmania                     [email-masked]
GPO Box 252C
Hobart TAS 7001
Australia