Chapter 3, Problem 1TY

Molecules that are found in living cells and contain the element ___________ are considered organic molecules.

1. a. hydrogen
2. b. carbon
3. c. oxygen
4. d. nitrogen
5. e. calcium

Summary Introduction

Introduction: After a lot of research, it has been found that all living organisms have organic molecules and macromolecules. Organic molecules and macromolecules may be carbohydrates, lipids, proteins, or nucleic acids. Organic molecules are named so because these molecules were seen first in living organisms.

Answer to Problem 1TY

Correct answer: Molecules that are found in living cells and contain the element carbon are considered as organic molecules. Hence, the correct answer is option b.

Explanation of Solution

Reason for correct answer:

Certain types of molecules were identified in all forms of life on Earth. All of these molecules contain carbon, therefore they are called as organic molecules. Organic molecules are studied under organic chemistry. Results of studies conducted by Wöhler and Kolbe showed that carbon is central to all organic molecules. Carbon is important because it has properties that make it suitable. Carbon can form four covalent bonds. It can exist as isomers and can bind to many different types of functional groups. Thus, carbon forms the backbone of all organic molecules.

Option b. is given as “carbon”.

Organic molecules are found in living cells and contain carbon. Hence, the correct answer is option b.

Reasons for incorrect answer:

Option a. is given as, “hydrogen”.

Organic molecules are based on the covalent interactions of hydrogens and carbons. Hydrogen provides organic molecules with the ability to form hydrogen bonds. However, the presence of hydrogen in organic molecules is not a necessity as there are certain organic molecules that do not contain hydrogen. Hence, option a. is incorrect.

Option c. is given as, “oxygen”.

Oxygen provides organic molecules with the ability to form hydrogen bonds and oxidative potential. However, the presence of oxygen in organic molecules is not a necessity as many organic molecules do not contain oxygen. Hence, option c. is incorrect.

Option d. is given as, “nitrogen”.

Nitrogen provides organic molecules with the ability to form hydrogen bonds. Nitrogen is important for the formation of amino acids and the genetic content of organisms. However, the presence of nitrogen in organic molecules is not a necessity as many organic molecules do not contain nitrogen. Hence, option d. is incorrect.

Option e. is given as, “calcium”.

Calcium is required in the skeletal system, muscular and nervous systems of the body. The presence of calcium in organic molecules is not a necessity as many organic molecules do not contain calcium. Hence, option e. is incorrect.

Hence, the options a., c., d. and e. are incorrect.

Conclusion

Thus, carbon is found in all living organisms and form an essential part of all organic molecules.