Aminoacids, have both an amino group and a carboxyl group in their structure. Which one of the following is an amino acid?

It is said that elemental composition of living organisms and that of inanimate objects (like earth’s crust) are similar in the sense that all the major elements are present in both. Then what would be the difference between these two groups? Choose a correct answer from among the following:

Many elements are found in living organisms either free or in the form of compounds. Which of the following is not found in living organisms?

An aminoacid under certain conditions have both positive and negative charges simultaneously in the same molecule. Such a form of aminoacid is called

Sugars are technically called carbohydrates, referring to the fact that their formulae are only multiple of C(H2O). Hexoses therefore have six carbons, twelve hydrogens and six oxygen atoms. Glucose is a hexose. Choose from among the following another hexose.