Is gross profit or net profit considered for taxes?

[Zachary Thompson]

I'll be as short and to the point as possible. I'm purchasing a property subject to the existing mortgage. To do so I'm using a business line of credit to pay for everything from start to finish. For sake of simplicity, lets say purchase price shows $50k, (remember it's a sub to deal so that $50k mortgage isn't paid off yet) and I sell the property for $200k. That shows a $150k gross profit. However, I borrowed $100k from a business line of credit which I had to pay back after the sale plus pay off the $50k of the existing mortgage. Leaving a net profit of $50k. Which number will be considered for tax purposes in this situation? Gross or net profit? 

P.S. I dont know if it matters but this transaction will be through my single member LLC