Arm pull ups really that good for the arms? I have been doing an assortment of bicep and tricep exercises and my new routine consists of pull ups, dumbbell curls, tricep extensions, and cable tricep extensions. Is this a good enough workout for the arms? Also I do the pull ups first and since I have started this I can't curl as much. Is this bad?
You're just full of fuckin' questions aren't you man? haha Pull-ups (with a pronated grip) are an exercise that primarily benefit the lat muscles (latissimus dorsi, also teres major). That's why a pulldown machine also exists; it's the same sort of movement but generally not as good (also, definitely not as good as a weighted pull-up). Chin-ups (with a supinated grip) are an exercise that primarily benefit the biceps muscles (primarily the biceps brachii but also the brachioradialis to a lesser extent). If you're trying to build up your biceps, do your DB curls with a supinated grip, and switch out pull-ups and instead do chin-ups (weighted chin-ups if you're at that level of fitness, but if not, do close-grip and regular-grip chin-ups). also, if you're tryna build some muscle on your triceps, do dips and triceps pushdowns/rope pushdowns. extensions are alright, but they're not a cornerstone triceps-building lift.
Yes they are plenty for the arms. You never need to use your biceps any more than you do at the gym. Functionally, they are limited; hence their small size. In my opinion, if you invest time in isolating the biceps, your time would be better spent investing it in a bigger muscle. At least with chin-ups and pull-ups you're hitting your back to get your money's worth of the time invested at the gym.