DNA - 2 Questions

yeah it's condensation.

it's deoxyribonucleic acid.

also, in organic chemistry, -COOH is the functional group for a carboxylic acid

A Bronsted-Lowry acid is a proton donor. The -COOH groups on the phosphates, not involved in ester bonding, lose a proton.

DNA is a deoxyribonucleic acid, because the small building blocks that construct the DNA are amino acids, these long chains of proteins produce the lattice structure of DNA. Now the formula for a protein is ... NH2-COOH
The NH2 being the amine group, and the -COOH being the acid, hence Deoxyribosenucleic acid.

This is factually incorrect. The building blocks of deoxyribonucleic acid are nucleic acids, which are made of a pentose sugar, a nitrogenous base and a phosphate group.

True, the nitrogenous base is the part where the group -COOH is.

Uh, no. None of the nitrogenouse bases contain COOH groups.
They are bases because they can accept a proton with one of their nitrogens.

then either its a part of pentose sugar or the phosphate group.

I haven't studied this area of Chemistry.