[opel65]

Hi, in the second reaction of the oxidative portion of the penthose phosphate pathway the product is 6-phosphogluconate. My question is if this compound is and aldehyde or a ketose. I had a question from my biochemistry professor: divide the products of all steps into aldehydes and ketoses. I've done so with all except this one as phosphogluconate does not have an additional R group, neither has it an H. its O=C-O^-.

Anyone know this one?

[Babcock_Hall]

Do you mean aldose or ketose?  That would be a little more symmetric.  If you assign oxidation numbers to the carbon atoms of 6-phosphogluconate, you will see that this compound falls into a unique category in this pathway.