Chapter 4, Problem 1TYK

Summary Introduction

Introduction:

Prokaryotes are mostly unicellular organisms and are divided into two domains, which are bacteria and archaea. They do not have membrane-bound organelles. The prokaryotic nucleus is not surrounded by the nuclear membrane and also lacks mitochondria.

Answer to Problem 1TYK

Correct answer:

The food energy is converted into chemical energy (ATP) in the plasma membrane of the prokaryotes.

Explanation of Solution

Justification for the correct answer:

Option (e) is plasma membrane. This is true as the plasma membrane metabolizes food molecules into the chemical energy. The plasma membrane of the prokaryotes constitutes some specialized molecules, which uses the food molecules and convert them into ATP (adenosine triphosphate). ATP is the energy currency of the cell and provides energy for various metabolic reactions. Hence, option (e) is correct.

Justification for the incorrect answers:

Option (a) is chromosome. This is false as the chromosome contains the genetic material DNA (deoxyribonucleic acid) or RNA (ribonucleic acid). The genetic material encodes the information which is required for the formation of protein. It does not convert food energy. It is simply passed on from one generation to the next. So, it is an incorrect option.

Option (b) is flagella. This statement is incorrect as the flagella uses the ATP (adenosine triphosphate) for the propelling movement and, thus, for locomotion. It is not involved in the formation of the ATP. So, it is an incorrect option.

Option (c) is ribosomes. This is incorrect because the ribosomes are involved in the conversion of the genetic information from DNA (deoxyribonucleic acid) to mRNA (messenger ribonucleic acid). The prokaryotic ribosomes consist of large and small subunits. It does not involve the generation of the ATP molecule. So, it is an incorrect option.

Option (d) is cell wall. This is incorrect because the cell wall provides protection and rigidity to the cell. It protects the cell from mechanical damage and, also, from the harsh conditions of the environment. So, it is an incorrect option.

Hence, options (a), (b), (c), and (d) are incorrect.

Conclusion

Thus, it can be concluded that the plasma membrane has a specialized molecular system and these molecular systems are responsible for the conversion of food energy into ATP (adenosine triphosphate).