CHAPTER 7: RESPIRATION7.1 The respiratory process in energy production

Tr.Rez@SB2013*

Tr.Rez@SB2013

Respirationthe oxidation of food substances in the mitochondria of cells to release energy

TYPES OF RESPIRATION

Types of RespirationAerobic respirationAnaerobic respirationCell respirationGaseous exchange

Cell respiration= internal respiration / tissues respirationoxidation of glucose molecules to produce energy, CO2 and H2O

Gaseous exchange= breathing / external respirationProcess of :transferring O2 from the surrounding medium (air or water) to cells & the elimination of the products of respiration (H2O & CO2) to the surrounding mediumInvolves : Inhalationexhalation

Aerobic Respiration

Aerobic RespirationTakes place in all living cells of plants, animals & in certain microorganismsProduction of energy in the presence of oxygenTakes place in mitochondriaProduce 2898 kJ energy

Anaerobic Respiration

Anaerobic respirationBreakdown of glucose to produce energy in the absence of oxygenInefficient because only a small amount of energy is releasedOccurs both in animal cells & plant cells

Anaerobic respirationAnaerobic respiration of glucose in animals produces lactic acid & energyEnergy produced : 210 kJ

Anaerobic respirationAnaerobic respiration of glucose in plants produces ethanol, carbon dioxide & energyEnergy produced : 210 kJ

Vigorous activity* Oxygen consumption exceeds supplyAnaerobic respiration takes place:* Glucose is broken down into lactic acid to produce some energyOxygen debt in muscles* Lactic acid causes muscle fatigue, pain & cramps

Lungs* Deep & rapid breathing to repay oxygen debLiver* 1/6 lactic acid is oxidised to produce energy* Energy converts 5/6 lactic acid back to glucosetMuscles:* Glucose returns to the muscles* Excess glucose is converted to glycogen for storage