The inputs to one cycle of the urea cycle are

• 1 molecule of aspartic acid, 1 molecule of ammonia, 1 molecule of carbon dioxide, 3 molecules of ATP
• 1 molecule of urea, 1 molecule of ammonia, 3 molecules of ATP and 1 molecule of fumaric acid
• 1 molecule of fumaric acid, 1 molecule of urea, 3 molecules of AMP
• None of the above