Questions about oxygen level in humans

[jnimagine]

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!

 

[epenguin]

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!

2. 25% oxygen in human arterial blood consumed by tissue metabolism

Yes, good enough for resting conditions. Good simple explanations in here http://people.eku.edu/ritchisong/301notes6.htm

Q1 reasoning is correct, you must be up against a miscopying or misprint or something. Knowing that you can probably work out what is meant.