Because carbohydrates are partially oxidised to organic acid, particularly malic acid without corresponding release of CO₂ but O₂ is consumed. Hence the RQ value will be zero.
\(\underset { Glucose }{ 2{ C }_{ 6 }{ H }_{ 12 }{ O }_{ 6 }+3{ O }_{ 2 }\rightarrow } \underset { malic\quad acid }{ 3{ C }_{ 4 }{ H }_{ 6 }{ O }_{ 5 }+3{ H }_{ 2 }O+Energy } \)
RQ of glucose in succulents = \(\frac { Zero \ molecule \ of \ { CO }_{ 2 } }{ 3 \ molecules \ of \ { CO }_{ 2 } } \) = 0 (Zero)

Anaerobic respiration occurs in man in muscles I at the time of exercising heavily. Blood supply is not sufficient for the oxygen need of the body. At that time lactic acid is produced in the muscle by anaerobic respiration.

The Amount of energy got from Anaerobic respiration is very less. One glucose molecule yields only 2 ATP I molecules. But this energy is sufficient for microbes since they are unicellular.

1) Anaerobic respiration is less efficient than the aerobic respiration.
2) Limited number of ATP molecules is generated per glucose molecule
3) It is characterized by the production of CO₂ and it is used for Carbon fixation in photosynthesis.

The ratio of volume of carbon dioxide given out and volume of oxygen taken in during respiration is called Respiratory Quotient or Respiratory ratio.

The transfer of electrons from reduced coenzyme NADH to oxygen via complexes I to IV is coupled to the synthesis of ATP from ADP and inorganic phosphate (Pi) which is called Oxidative phosphorylation.

1) Alcoholic fermentation
2) Lactic acid fermentation
3) Mixed acid fennenatation.

a) cyanide
b) Oligomycin

Abnormal rise in respiratory rate during ripening in fruits is called climacteric. Eg: Banana, Mango.

The synthesis of glucose from certain noncarbohydrate carbon substrates such as proteins and lipids are called gluconeogenesis.

Carbon di oxide and light.

Floating Respiration and Protoplasmic respiration based upon the nature of respiratory substrate.

At night time plants take oxygen and release carbon di oxide. As a result carbon di oxide will be abundant around the tree. In the night plants only respire. Photosynthesis does not take place by which oxygen can be released.

If the respiratory substrate carbohydrate is incompletely oxidised the RQ value will be infinity
\(\underset { Glucose }{ { C }_{ 6 }{ H }_{ 12 }{ O }_{ 6 } } \rightarrow 2C{ O }_{ 2 }\uparrow +\underset { Ethyl\quad alcohol }{ 2{ C }_{ 2 }{ H }_{ 5 }OH+Energy } \)
RQ of glucose Anaerobically = \(\frac { 2 \ molecules \ of \ C{ O }_{ 2 } }{ zero \ molecule \ of \ { O }_{ 2 } } \)
= \(\infty \)(infinity

Glycolysis .pathway of respiration is common to all living organisms (aerobic and anaerobic). It occurs in the cytoplasm of the cell. In Glycolysis, one molecule of glucose is converted into two molecules of pyruvic acid.