P Bowles wrote:

In article <3F71D60F.4030408@pacbell.net>, John Harshman
<jharshman.diespamdie@pacbell.net> writes:

All except for being wrong. Chlorophyll does have magnesium in it, and
it is very similar to heme (not hemoglobin)

As I said, it's a pigment rather than a protein, as is heme, while haemoglobin
is a protein. The difference in structure is crucial, as it is the globin and
cyanin components in blood-transport systems that bind the oxygen,

Beg pardon? It's the heme that binds the oxygen. That's what it's for.
The globin is just there to increase specificity and alter the binding
properties so the heme binds and lets go at the right times.

leading to
the next point: chlorophyll is not an oxygen transport mechanism, but a light
absorber that forms one link in the electron transport system, a very different
function. I'll admiot that I wasn't aware of the magnesium component, but based
on its very different properties and structure the essential point that
chlorophyll is not a 'plant equivalent' of haemoglobin remains valid.

Its structure is almost identical to heme. It's very likely that the
metabolic pathways by which they are produced are descended from the
same ancestral pathways, so in some weird sense chlorphyll and heme are
"paralogs".

Look. Jabriol was wrong about much of what he said. But so are you.
Jabriol was right about a few things. You are probably right about more
things, though I haven't counted. But you need to acknowledge errors here.