Cook pasta according to the direction on the package. Five minutes before it's done, stir the vegetables into the pot.
Drain, reserving 1/2 cup of the cooking liquid. Return pasta and veggies to the pot. Stir in Alfredo sauce, reserved cooking liquid, shrimp, cheese, and lemon juice and cook until warm. Garnish with lemon. To round out the meal, serve the pasta with a green salad.