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0:00
Hello. My name is Susan
Fairweather-Tait.
I'm professor of human nutrition
in the Norwich Medical School
at the University of
East Anglia, in the UK.
I'm going to be talking
to you about molybdenum.
0:16
Molybdenum-containing enzymes
catalyse redox reactions.
They do this via the conversion
between different
oxidation states.
That's from molybdenum
4+ to molybdenum 6+,
and reverse.
Molybdenum is a structural
constituent of molybdopterin.
This is a cofactor that is
synthesized by the body,
and it's required for the
function of four enzymes.
These are sulphite
oxidase, xanthine oxidase,
aldehyde oxidase, and
mitochondrial ARC.
Now these four enzymes
all metabolise
sulphur-containing amino acids
and heterocyclic compounds,
including purines
and pyrimidines.
1:01
Molybdenum is present
in nearly all foods.
It's only found
in trace amounts,
and it's mainly as
soluble molybdates.
In plant and animal foods,
the content differs quite a lot
depending on the levels of soil.
These soil levels of
molybdenum are quite variable,
but generally speaking,
foods which are rich in
molybdenum include pulses,
cereal grains and
grain products,
offal, that's liver and kidney,
and nuts.
1:31
As I explained before,
food molybdenum is present
as water-soluble molybdates,
and these are readily absorbed
from the digestive tract,
but little is known
about the mechanism
or the site of absorption.
We do know absorption
is passive,
and we know it's not saturable.
If we look at the total diet,
the mean absorption in
total is about 80%,
but it does vary between
individual foods.
For example, from kale,
the absorption is
as high as 86%,
but from soy,
it's been measured
to be as low as 57%.
We also know that black tea
reduces absorption
of molybdenum,
but we don't know the mechanism
by which this occurs.
