Question

5. Mammalian urine contains a lot of urea. Urea (nitrogenous waste) is a waste product resulting from the digestion of which of the following molecules? a. carbohydrates and fats b. protein and nucleic acids c. nucleic acids and carbohydrates d. fats and proteins

Answer 1

Mammalian urine contains a lot of urea. Urea (nitrogenous waste) is a waste product resulting from the digestion of protein and nucleic acids. As a result of digestion of protein molecules amino acids are formed. These amino acids result in the formation of ammonia which is acted upon by liver enzymes to form urea. Urea is removed from the body as urine. Nucleic acids are converted to pentose phosphates and nitrogenous bases as a result of digestion. Nitrogen is removed from the body in the form of urea as urine. Hence option (b) is the correct answer.

Carbohydrates are converted to monosaccharides like glucose, fructose and galactose as a result of digestion.

Lipids are converted to fatty acids and monoglycerides as a result of digestion.

Hence option (a) carbohydrates and fats

Option (c) nucleic acids and carbohydrates and

Option (d) fats and proteins

Are incorrect

because in option(c) carbohydrates do not contibute to formation of urea and in option (d) fats donot contribute to the formation of urea.

Only option(b) protein and nucleic acids is the correct option.