CBSE Questions for Class 11 Medical Biology Respiration In Plants Quiz 17 - MCQExams.com

• One molecule of glucose forms two molecules of pyruvic acid as the end product of glycolysis.
• At the 6$$^{th}$$ step of glycolysis, 2 molecules of 1,3 diphosphoglyceraldehyde convert to 2 molecules of 1,3 diphosphoglyceric acid by converting 2 NAD+ to 2 NADH$$_2$$.
• So, 2 molecules of NADH$$_2$$ are produced which yields 6 ATP through ETS during aerobic respiration.

•  One ATP yields 7.15 kcal energy and energy released by one molecule of glucose is 38 ATP or 1164 kJ of energy. 
• The pentose phosphate pathway or phosphogluconate pathway was discovered by Otto Warburg.
• The respiratory quotient is the ratio of the volume of $$CO_2$$ produced to the volume of $$O_2$$ consumed in respiration. For fats such as tripalmitin ($$C_{51}H_{98}O_{6}$$) is 0.7.
• One molecule of glucose on complete oxidation liberate 2870kJ of energy.

• Glycolysis is a series of reactions that extract energy from glucose by splitting it into two three-carbon molecules called pyruvate. 
• Glycolysis takes place in the cytosol of a cell, and it can be broken down into two main phases: the energy-requiring phase and the energy-releasing phase. 
• When one molecule of phosphoglyceraldehyde is converted to one molecule of pyruvate, one NADH is produced.
• Thus, during the conversion of four molecules of phosphoglyceraldehyde to pyruvate, four NADH are generated. 

1. Glycolysis
2. Krebs cycle 
3. Terminal oxidation

• Respiration occur in these step - glycolysis, Krebs cycle, and oxidative phosphorylation occurs in the electron transport chain.
• So the first step glycolysis occur in both aerobic and aerobic condition and in final step two molecule of pyruvic acid and two molecule of ATP is produce. connecting link  between glycolysis and Krebs cycle is the pyruvic acid is converted to acetyl CoA. 
• This acetyl CoA after the two processes form the 2 ATP, 6 NADH, and 2FADH and carbon dioxide . 
• After that in the electron transport chain, where most of the ATP is produced, the hydrogen that is removed from the products in previous steps are forwarded to mitochondria, where this hydrogen react  with oxygen molecules and water molecule form. 

36 ATPs are produced in Aerobic Respiration involving the complete breakdown of glucose molecule into carbon-dioxide and water using oxygen as final electron aceptor

Complete oxidation of glucose molecule takes place in 3 sequential reactions -

1.Glycolysis occuring in cytoplasm

2.Kreb cycle occuring in mitochondrial matrix

3 Electron transport chain (ETC )and oxidative phosphorylation occuring in inner mitochondrial membrane . So,total number of ATPs produced in aerobic respiration are

Glycolysis - 6/8 ATPs

Link reaction and kreb cycle - 30ATPs

Total -36/38 ATPs.

So, the correct option is 'Option A'.

• During the Krebs cycle, 6 oxygen molecules are involved during the oxidation of pyruvate.
• These 6 oxygen molecules formed from 12 atoms of oxygen.
• Since in the Krebs cycle 2 molecules of pyruvate are formed, complete oxidation of pyruvate requires 6 atoms of oxygen.