ENERGY

nAll living things need a continuous supply of energy to carry on their life  activities. Some of these energy is needed for physical or mechanical work.

LIVING THINGS TAKE ENERGY FROM FOODSTUFFS BY CELLULAR RESPIRATION.

CELLULAR RESPIRATION    

nThe break down of glucose with the use of oxygen or enzymes is called

  cellular  respiration.

            Types of Respiration

There are two types of respiration.

 These are

 1-Anaerobic  respiration.   

            (Fermentation)

 2-Aerobic  respiration.

ANAEROBIC RESPIRATION

*Anaerobic respiration is form of respiration that does not requires oxygen for the release of energy from food molecules, such as glucose.

*Yeast and many forms of bacteria produce energy by anaerobic respiration(fermentation)

Characteristics of anaerobic                                    respiration

*Anaerobic respiration takes place in cytoplasm.

*Little energy is produced and stored as ATP

*Controlled by an enzyme.

*Oxygen is not used

*Alcohol or Lactic acid is produced

       Types of anaerobic                                                       respiration

*Fermentation is divided into 3        types according to their end product.

* Alcoholic  fermentation.

* Lactic acid fermentation.

* Acedaldehyde fermentation     

Alcoholic fermentation

C6H12O6 + 2ATP

Lactic acid fermentation

C6H12O6 + 2ATP

ENERGY PRODUCTION

4 ATP molecules are formed per glucose molecule. However two ATP are used to energize of glucose molecule. So the net energy output of fermentation is 2 ATP for a glucose molecule.

AEROBİC RESPİRATİON

 *Anaerobic respiration is form of respiration that requires oxygen for the release of energy from food molecules, such as glucose.

Characteristics of  aerobic respiration

*Aerobic respiration takes place in mitochondria of the cell.

*Large amounts of energy is produced and stored as ATP end of the aerobic respiration.

*Controlled by an enzyme.

*Oxygen is used. 

*CO2  and  H2O are produced.  

Reaction of         Aerobic Respiration        

C6H12O6 + 6 O2

Steps of Aerobic                     respiration

            1-Glycolysis - in in cytoplasm.

   2-Krebs cycle - in matrix

   3-ETS    in cristae

                        Glycolysis

 *The splitting of a glucose into two molecules of pyruvic acid is called glycolysis.

*It takes place in cytoplasm.

*The net profit is 2  ATP

*This step is the same in both aerobic and anaerobic respiration

GLYCOLYSIS

nIf there are oxygen molecules in mitochondrion pyruvate changes to acetyl CoA (Ac Co A).

n2 NADH2 and CO2 are produced in this reaction.

nAc CoA has 2 carbon  atoms.

                        Krebs Cycle

 *The series of chemical reactions that begin with the Ac Co A is called krebs cycle

In Krebs cycle

n2 acetyl CoA

n6 NADH+H,

n2 FADH2

n2 ATP  are produced.

    Electron Transport                                   System                      

*Highly organized system of enzymes and coenzymes is called Electron Transport System (chain)

* A series of oxidation � reduction reactions take place

*34 ATP are produced by the ETS for each molecule of glucose.

HYDROGEN ACCEPTOR

nHydrogen atoms are carried by NAD, FAD, cytochromes and  O2. These are called  hydrogen (electron) acceptor. Oxygen becomes the final hydrogen acceptor, combining  with  hydrogen to form water.   

Calculation of ATP Energy

TOTAL

Comparison  of  Aerobic  and  Anaerobic  Respiration

 Aerobic respiration                                     

1-Uses oxygen.

2-CO2  and  H2O are produced.          

3-Large amount of energy is released.

4-Seen in many organisms.                 

5-CO2  is always made.                      

Anaerobic respiration

1-Does not use oxygen  

2-Alcohol or Lactic acid is produced.

3-Small amount of energy is released

4-Seen in some simple organisms.

5-CO2  is sometimes made.

Similarities Between Aerobic and Anaerobic respiration

*          Both of them have glycolysis   *           Controlled by an enzyme.

*          CO2 is produced

*          The formation of ATP