LECTURE                                                              RESPIRATION

In this lecture you will learn:


glycolysis occurs in cytoplasm

1. GLUCOSE (6C) is broken down to (2) 3C molecules (Pyruvate)

2.  Energy is sucked out of the bonds of the 3C molecules to make an ATP, so net is 2 ATP per glucose

NO OXYGEN - FERMENTATION - anaerobic in animals

3C  is converted to Lactic acid (which causes stiff and painful muscles)

in yeast 3C  is decarboxylated forming CO2 and Ethanol
wine ... Alcoholic Fermentation

Anaerobic Glycolysis uses only about 7% of available energy<------<<<----

In both cases of fermentation hydrogens are added but only in the case of ethanol fermentation is CO2 given off.  Reason why wine can be "bubbly". 


1. 3C is transported to mitochondria

2. first CO2 is plucked off to leave 2C molecules

3. then goes into KREBS CYCLE aka The Citric Acid Cycle

(3C - CO2 = 2C)

4. the point is to burn the CH to CO2 .. in the process the hydrogen is dumped onto oxygen > H2O and to take high energy electrons (covalent bonds)  and suck the energy out of them to make ATP

the 2C unit is bound to a 4C unit (oxaloacetate) to make a 6C unit called CITRIC ACID

(2C + 4C = 6C)

5.  As the CO2 are removed, the electrons are handed off to "handlers" like NAD and the hydrogens come along (NADH).  A total of 2 CO2 are popped off the end regenerating the oxaloacetate 4C unit ready to take another 2C unit.  The NADH now takes the electrons to the electron transport factory where the energetic electrons are used to make ATP.

(6C - CO2, 5C - CO2 = 4C) 


aka chemiosmosis Click here

6. Now the electrons are handed off to the electron transport proteins where they use little bits of energy in turn to push hydrogen ions onto one side of the membrane .. this sets up a voltage gradient, just like a battery

7.  When the voltage gradient is high enough, the hydrogens can only get across at the ATP synthetase and their pushing thru results in ADP being phosphorylated to ATP.  The hydrogen now meets up with the oxygen and makes H2O.

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Discuss what you know about glycolysis.  What is broken down, into what, how much ATP is made, where does it occur, who can do this, does it need oxygen?
What are some of the end products of fermentation, how do these products affect you?  What is the purpose of fermentation?
What is the Kreb's cycle?  where does it happen?  does it require oxygen? where do the electrons go? what are the end products of Krebs and electron transport?  how much ATP is made?
Why is oxygen needed for respiration to occur?
How is ATP made?  How is electron transport/respiration like a battery?