While the pasta water is coming to a boil, do your necessary chopping and measuring. In a heated frying pan place olive oil and garlic and onion, saute for a minute on low. Add tomato sauce and lemon juice, and crushed red pepper. Next, add shrimp and heat thoroughly at low temperatures. (If you heat them on too high a temperature they will become tough). Add in drained artichoke hearts. Pour sauce over hot pasta and serve with grated Parmesan Cheese.