CBSE Class 11 Biology NCERT Solutions: Chapter 14, Respiration in Plants

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In this article, you will get the NCERT Solutions for CBSE class 11 Biology chapter 14, in Plants. All the questions have been solved in the most appropriate and simple way so as to help students access the right study material for the exam preparation.

Some of the questions and their solutions from NCERT Solutions for Class 11: Respiration in Plants, are as follows:

Q. What are respiratory substrates? Name the most common respiratory substrate.

Ans. In the process of respiration, those compounds which get oxidised to release energy are called respiratory substrates. The most common respiratory substrate is glucose.

Q. Explain ETS.

Ans. Electron transport system (ETS) is the metabolic pathway through which the electron passes from one carrier to another. It is located in the inner mitochondrial membrane.

(i) Electrons from NADH that produced in the mitochondrial matrix during citric acid cycle, are oxidized by an NADH dehydrogenase (Complex I). These electrons are then transferred to ubiquinone which is located within the inner membrane.

(ii) Ubiquinone also receives reducing equivalents via FADH2 (Complex II). FADH2 is generated during oxidation of succinate in the citric acid cycle.

(iii) The reduced ubiquinone (ubiquinol) is then oxidised with the transfer of electrons to cytochrome-c via cytochrome-bc1 complex (complex III).

(iv) The outer surface of the inner membrane has a small protein, cytochrome-c attached to it that acts as a mobile carrier for transfer of electrons between complex III and IV.

(v) Complex IV refers to cytochrome c oxidase complex containing cytochromes a and a3, along with two copper centres.

(vi) When the electrons pass from one carrier to another via complex I to IV in the electron transport chain, they are coupled to ATP synthase (complex V). This coupling is necessary for the production of ATP from ADP and inorganic phosphate. The amount of ATP produced depends on the molecule, which has been oxidised.

CBSE Class 11 Biology Syllabus 2018 - 2019

Q. Define RQ. What is its value for fats?

Ans. Respiratory quotient (RQ) or respiratory ratio can be defined as the ratio of the volume of CO2 evolved to the volume of O2 consumed during respiration. The value of respiratory quotient depends on the type of respiratory substrate. Its value is one for carbohydrates. However, it is always less than one for fats as fats consume more oxygen for respiration than carbohydrates. It can be illustrated through the example of tripalmitin fatty acid, which consumes 145 molecules of O2 for respiration while 102 molecules of CO2 are evolved. The RQ value for tripalmitin is 0.7.

Q. What is the significance of step-wise release of energy in respiration?

Ans. The process of aerobic respiration is divided into four phases – glycolysis, TCA cycle, ETS, and oxidative phosphorylation. It is generally assumed that the process of respiration and production of ATP in each phase takes place in a step-wise manner. The product of one pathway forms the substrate of the other pathway. Various molecules produced during respiration are involved in other biochemical processes. The respiratory substrates enter and withdraw from pathway on necessity. ATP gets utilized wherever required and enzymatic rates are generally controlled. Thus, the step-wise release of energy makes the system more efficient in extracting and storing energy.

Get the complete the NCERT solutions for Class 11: Respiration in Plants, from the following link:

Class 11 Biology NCERT Solutions: Respiration in Plants

Students may download the NCERT solutions for Class 11 Biology chapter- Respiration in Plants, in the form of PDF. 

Class 11 Biology NCERT Chapter: Respiration in Plants

At the time of solving the NCERT questions, if you find yourself puzzled or unaware of any particular concept, then you should go through the NCERT chapter once again. Taking a thorough reading of the theories given in NCERT book will help you understand the problem discussed in a question and then come with an appropriate answer.

Main topics discussed in Class 11 Biology chapter: Respiration in Plants are:

  • Do plants breathe?
  • Glycolysis
  • Fermentation
  • Aerobic respiration
  • Tricarboxylic acid cycle
  • Electron transport system (ets) and oxidative phosphorylation
  • Respiratory balance sheet
  • Amphibolic pathway
  • Respiratory quotient

Find below the link to download the complete Chapter:

Class 11 Biology NCERT Chapter: Respiration in Plants

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