1. Place a large pot of water over high heat to boil. Salt the water and cook the angel hair pasta until al dente, with a bite. Reserve a couple of ladles of cooking water before draining the pasta.
2. While the pasta cooks. Heat a large skillet over medium heat. In a bowl combine the garlic, parsley, salt, pepper, and olive oil. Toss the shrimp with half of the garlic mixture to coat evenly. Transfer the shrimp to the hot sauté pan. Add lemon ½ the lemon zest, and cook for about 2 to 3 minutes on each side, until the shrimp are firm and opaque. Remove shrimp from skillet and cover to keep warm.
3. Return skillet to burner. Add the reserved garlic mixture and the red pepper flakes; cook for 1 to 2 minutes, or until the garlic is lightly golden brown. Add the wine to the skillet and cook for 1 minute, then add 2 ladles of the pasta cooking water and the lemon zest and juice and continue to cook for 2 minutes. Add the butter and stir until melted. Add the drained angel hair pasta, and toss to coat. Taste to adjust the seasoning with salt and pepper. Divide the pasta and shrimp among 4 serving plates.