How does the Defense Booster consumable work exactly?

The description just says it "Increases your Defense for 30 seconds".
Does anyone know by how much and what defense exactly?
I'd like to know what Attack Up does as well.

I'm actually looking into this right now.
Give me about 30 mins or so and I'll have a good answer.
Previously I thought it was a flat boost (about UV med to everything). But I'm attempting to confirm that now.
Edit: Posted result of my tests below. I was wrong in this post.

Well, Attack Up increases your attack damage slightly, if you have the damage numbers shown then you can see the difference before and after it is picked up.
I'm not sure on the exact numbers of increase, but I'd say, again, slightly greater.

If I remember correctly, defense up orbs increase the defense of your current gear by a percentage. I want to say something like 17% increase, but I don't know for certain. If they haven't changed how that all works, that is. Defense up won't be helpful to someone wearing the divine set when fighting slimes, as there is no piercing or normal defense to increase.

It increases your defence by 25% (I think). For more on defence, you could have a look at the wiki:
http://wiki.spiralknights.com/Defense

25% looks accurate.
Then again, we don't completely know how armor works just yet.
I got values suggesting 25% increase in "armor value" when inside Zeddy's "predictable" range (2*armor less than damage).
UVs do not get this boost.

How much defense is blocked with maxed out Flame Barrier and a Defense orb from 1) normal drops and 2) iron heart attack?

It functions on a percentage basis, U-77654, so the increase would be based on your armor- if you're wearing chaos set, which you've heated as your "main armor", you'll get a much bigger buff than if you're wearing volcanic plate set- which is almost certainly not your main armor, and almost certainly isn't heated.
The iron heart attack orbs from the normal defense are the same as the ones from the iron heart attack. I'm not sure if the flame barrier stacks with others or not though.

Defense Up, Speed Up, and Attack Up all increase your raw defense/speed/attack by 20%.
I think it just negates some of the damage done to you.
Bopp please back me up >.>