David Cook


Hans Krebs Tower, Biochemistry Building, Oxford


Hurrying to be seated before the start

of the lecture, I squeeze an extra place

      on the paternoster,

      not noticing you, who are there already.


Getting off three floors up, I flail, and lurch

to the left as I step out on air and

      come down with a jolt,

      my balance reflexively corrected.


I’m uncertain where I ought to be going.

The pods climb and fall in linked motion.

      ‘At last!’ - I know you at once -

      ‘I was there in the lift, you looked through me.’


You lead the way briskly. I ask ‘A round trip?

Is that how you reached me?’ ‘By transgression.’

      You smile. ‘So - up, sideways

      back down’ - ‘Yes, motif of rejuvenation’.


We sit near the front. An old colleague of Krebs

expounds the motive power of Krebs Cycle.

      And the building bears his name.

      ‘Pinch yourself, he may be sitting behind us.’


Respiration at the cellular level -

when the organism dies the cycle seizes,

      or after a thousand shocks

      cells and tissues persuade us to die.


‘An unlikely place to find time together.’

‘We should feel the surprise as a blessing.’

       The paternoster was judged

       unsound. And later so was the building.



Hans Krebs won the Nobel Prize in 1953 for finding the metabolic pathway which was known as the Citric Acid Cycle or named for Krebs himself. It is found in the cells of all plants, animals and fungi - the only exceptions being the few micro-organisms which do not require oxygen to live. The Krebs building in Oxford had another emblematic cycle, the paternoster, a continuous lift without doors. I remember concentrating hard when I used it. The strange meeting was poignant and as indicated, a blessing. Feed back loops can be regulative (negative) or explosive (positive). Dreams too, perhaps.