Question about oxygen in human...

[yj90]

1. The % of hemoglobin bound with Oxygen is different at high and low carbon dioxide concentrations when the partial pressure of O2 equals 0mm Hg
True or false??
This should be false right...? if partial pressure is 0... Hb can't bind to any oxygen in the first place... is my reasoning correct?

2. 25% oxygen in human arterial blood consumed by tissue metabolism
True or false
i'm not sure if it's actually 25%..... :S

I would greatly appreciate any help!
Thank you!

[Darby]

Hemoglobin affinity changes with pH, and HCO3 (CO2 in solution) concentration affects plasma pH, but I have no idea of how the numbers work.

There's very little tissue distribution from arteries - the linings are too thick, distribution happens from capillaries. Sounds like a trick question.