Cellular Respiration:
   
Cellular Respiration:
the release of chemical energy for cellular use.

 

 

 

 

      
     
 

The chemical equation for respiration is:

   
C6H12O6 + 6O2
6CO2 + 6H2O
     
Glucose + Oxygen Carbon Dioxide + Water
 
 
      Notice that Respiration is the reverse of Photosynthesis!
       
                           
                    Adenosine triphosphate - ATP the molecule organisms can actually use for energy.
                               
 

Glucose stores the sun's energy in chemical form.

Respiration the breaking down of pyruvic acid using molecular oxygen.

Glycolysis
Splits the 6-carbon glucose molecule into two 3-carbon pyruvic acid molecules and 2 ATP molecules. This process is anaerobic, not requiring the presence of molecular oxygen.


Fermentation - the breaking down of pyruvic acid without using molecular oxygen.

At this point, there are three possibilities:

1. Aerobic respiration -

A. The Krebs Cycle, also known as the Citric Acid Cycle, produces 2 ATP molecules, 10 carrier molecules, and CO2 from each glucose molecule.

B .The Electron Transport Chain then produces 34 ATP molecules and H2O from the carrier molecules.

 
           
                               
 
 
                    
    The bulk of a cell's ATP must be produced in the mitochondria.
To be energy efficient, particles must move through the membrane with little energy expense.		    
                     
                                 
                     
    Electron transport produces an uneven charge on the mitochondria membrane.
This allows protons to move through the membrane by electrical charge attraction.		    
                     
                                   
                       
      Protons now move through the membrane and are used by ATP synthase enzyme to make ATP.    
                       
                                   
       

2. Lactic acid fermentation - Occurs in animal cells due to a lack of oxygen, causing muscle soreness as lactic acid builds up. While no ATP is produced, a carrier compound is produced, allowing glycolysis to continue.


3. Alcoholic fermentation - Occurs in some plants and unicellular organisms. The process converts pyruvic acid into ethyl alcohol and a carrier compound, which allows glycolysis to continue.

   
                                   
 

Comparing energy yield:

* Aerobic respiration (with oxygen) can produce 38 ATP molecules from each glucose molecule.
* Anaerobic respiration (without oxygen) only allows glycolysis to continue which produces 2 molecules from each glucose molecule.
* Therefore, aerobic respiration is some 19 times as efficient as anaerobic respiration.

   
         
 

17. Which of the following chemical equations represents cellular respiration?

A. 6CO2 + 6H2O C6H12O6 + 6O2
B. 14H+ + Cr2O7-2 + 6I - 2Cr+3 + 3I2 + 7H2O
C. C6H12O6 + 6O2 6CO2 + 6H2O
D. C7H16 + 11O2 7CO2 + 8H2O
 

46. The diagram above shows some of the stages in cellular respiration. Which of the following gives the stages in the correct order?

A. Electron transport system, Krebs cycle, glycolysis
B. Glycolysis, electron transport system, Krebs cycle
C. Krebs cycle, glycolysis, electron transport system
D. Glycolysis, Krebs cycle, electron transport system
 
 
 

1. Study this website about ATP. Write a paragraph explaining why the three phosphate groups in an ATP molecule are the key to ATP being used for cellular energy.
2. Use this website to write a paragraph explaining what happens when lactic acid builds up in muscles?
3. How many carbon atoms are in a molecule of pyruvic acid?
4. What does the term "anerobic" mean?

5. get a diagram from Mr. Humble and follow the instructions on the attached page.