Learn Portuguese (Portugal): Trabalhamos muito para que a instituição arrecade mais dinheiro. - We are working hard so that the charity raises more money.

The phrase para que (so that, or in order that) always requires the subjunctive. It introduces the purpose or goal of our work, which is an intention rather than a guaranteed fact. Because arrecadar (to raise or collect) is an -ar verb, its present subjunctive form for a instituição ends in -e, making it arrecade.

Could I just say para a instituição arrecadar instead of para que a instituição arrecade?

Yes! If you drop the que, you no longer need the subjunctive and can use the personal infinitive instead. Both para que a instituição arrecade and para a instituição arrecadar mean the exact same thing. Portuguese speakers often prefer the personal infinitive version in everyday speech.

Does instituição specifically mean charity?

It literally translates to institution, but it is very commonly used as a shorthand for instituição de caridade (charity) or instituição de solidariedade (non-profit organization). In this context, it clearly refers to a charitable group.

Why is trabalhamos translated as we are working instead of we work?