Bring a large pot of lightly salted water to a boil. Add penne and cook, stirring occasionally, until tender yet firm to the bite, about 11 minutes. Drain and set aside.
Meanwhile, melt butter in a 10-inch skillet over medium heat. Add red pepper strips and garlic; cook until peppers are tender and crisp, 2 to 3 minutes. Add shrimp and lemon juice; stir constantly until shrimp turn bright pink on the outside and the meat is opaque, 4 to 6 minutes. Add cooked pasta and lemon zest and toss lightly to coat. Serve sprinkled with Parmesan cheese and parsley.